Moved vendored js/css into public/vendor and documented sources (#1484) (#2241)

* Cleaning up public/ and documenting js/css libs.

This commit mostly addresses #1484 by moving vendor'ed plugins into a
vendor/ directory and documenting their upstream source and license in
vendor/librejs.html.

This also proves gitea is using only open source js/css libraries which
helps toward reaching #1524.

* Removing unused css file.

The version of this file in use is located at:
  vendor/plugins/highlight/github.css

* Cleaned up librejs.html and added javascript header

A SafeJS function was added to templates/helper.go to allow keeping
comments inside of javascript.

A javascript comment was added in the header of templates/base/head.tmpl
to mark all non-inline source as free.

The librejs.html file was updated to meet the current librejs spec. I
have now verified that the librejs plugin detects most of the scripts
included in gitea and suspect the non-free detections are the result of
a bug in the plugin. I believe this commit is enough to meet the C0.0
requirement of #1534.

* Updating SafeJS function per lint suggestion

* Added VERSIONS file, per request

public/vendor/plugins/codemirror/mode/webidl/webidl.js

@@ -0,0 +1,195 @@
+// CodeMirror, copyright (c) by Marijn Haverbeke and others
+// Distributed under an MIT license: http://codemirror.net/LICENSE
+
+(function(mod) {
+  if (typeof exports == "object" && typeof module == "object") // CommonJS
+    mod(require("../../lib/codemirror"));
+  else if (typeof define == "function" && define.amd) // AMD
+    define(["../../lib/codemirror"], mod);
+  else // Plain browser env
+    mod(CodeMirror);
+})(function(CodeMirror) {
+"use strict";
+
+function wordRegexp(words) {
+  return new RegExp("^((" + words.join(")|(") + "))\\b");
+};
+
+var builtinArray = [
+  "Clamp",
+  "Constructor",
+  "EnforceRange",
+  "Exposed",
+  "ImplicitThis",
+  "Global", "PrimaryGlobal",
+  "LegacyArrayClass",
+  "LegacyUnenumerableNamedProperties",
+  "LenientThis",
+  "NamedConstructor",
+  "NewObject",
+  "NoInterfaceObject",
+  "OverrideBuiltins",
+  "PutForwards",
+  "Replaceable",
+  "SameObject",
+  "TreatNonObjectAsNull",
+  "TreatNullAs",
+    "EmptyString",
+  "Unforgeable",
+  "Unscopeable"
+];
+var builtins = wordRegexp(builtinArray);
+
+var typeArray = [
+  "unsigned", "short", "long",                  // UnsignedIntegerType
+  "unrestricted", "float", "double",            // UnrestrictedFloatType
+  "boolean", "byte", "octet",                   // Rest of PrimitiveType
+  "Promise",                                    // PromiseType
+  "ArrayBuffer", "DataView", "Int8Array", "Int16Array", "Int32Array",
+  "Uint8Array", "Uint16Array", "Uint32Array", "Uint8ClampedArray",
+  "Float32Array", "Float64Array",               // BufferRelatedType
+  "ByteString", "DOMString", "USVString", "sequence", "object", "RegExp",
+  "Error", "DOMException", "FrozenArray",       // Rest of NonAnyType
+  "any",                                        // Rest of SingleType
+  "void"                                        // Rest of ReturnType
+];
+var types = wordRegexp(typeArray);
+
+var keywordArray = [
+  "attribute", "callback", "const", "deleter", "dictionary", "enum", "getter",
+  "implements", "inherit", "interface", "iterable", "legacycaller", "maplike",
+  "partial", "required", "serializer", "setlike", "setter", "static",
+  "stringifier", "typedef",                     // ArgumentNameKeyword except
+                                                // "unrestricted"
+  "optional", "readonly", "or"
+];
+var keywords = wordRegexp(keywordArray);
+
+var atomArray = [
+  "true", "false",                              // BooleanLiteral
+  "Infinity", "NaN",                            // FloatLiteral
+  "null"                                        // Rest of ConstValue
+];
+var atoms = wordRegexp(atomArray);
+
+CodeMirror.registerHelper("hintWords", "webidl",
+    builtinArray.concat(typeArray).concat(keywordArray).concat(atomArray));
+
+var startDefArray = ["callback", "dictionary", "enum", "interface"];
+var startDefs = wordRegexp(startDefArray);
+
+var endDefArray = ["typedef"];
+var endDefs = wordRegexp(endDefArray);
+
+var singleOperators = /^[:<=>?]/;
+var integers = /^-?([1-9][0-9]*|0[Xx][0-9A-Fa-f]+|0[0-7]*)/;
+var floats = /^-?(([0-9]+\.[0-9]*|[0-9]*\.[0-9]+)([Ee][+-]?[0-9]+)?|[0-9]+[Ee][+-]?[0-9]+)/;
+var identifiers = /^_?[A-Za-z][0-9A-Z_a-z-]*/;
+var identifiersEnd = /^_?[A-Za-z][0-9A-Z_a-z-]*(?=\s*;)/;
+var strings = /^"[^"]*"/;
+var multilineComments = /^\/\*.*?\*\//;
+var multilineCommentsStart = /^\/\*.*/;
+var multilineCommentsEnd = /^.*?\*\//;
+
+function readToken(stream, state) {
+  // whitespace
+  if (stream.eatSpace()) return null;
+
+  // comment
+  if (state.inComment) {
+    if (stream.match(multilineCommentsEnd)) {
+      state.inComment = false;
+      return "comment";
+    }
+    stream.skipToEnd();
+    return "comment";
+  }
+  if (stream.match("//")) {
+    stream.skipToEnd();
+    return "comment";
+  }
+  if (stream.match(multilineComments)) return "comment";
+  if (stream.match(multilineCommentsStart)) {
+    state.inComment = true;
+    return "comment";
+  }
+
+  // integer and float
+  if (stream.match(/^-?[0-9\.]/, false)) {
+    if (stream.match(integers) || stream.match(floats)) return "number";
+  }
+
+  // string
+  if (stream.match(strings)) return "string";
+
+  // identifier
+  if (state.startDef && stream.match(identifiers)) return "def";
+
+  if (state.endDef && stream.match(identifiersEnd)) {
+    state.endDef = false;
+    return "def";
+  }
+
+  if (stream.match(keywords)) return "keyword";
+
+  if (stream.match(types)) {
+    var lastToken = state.lastToken;
+    var nextToken = (stream.match(/^\s*(.+?)\b/, false) || [])[1];
+
+    if (lastToken === ":" || lastToken === "implements" ||
+        nextToken === "implements" || nextToken === "=") {
+      // Used as identifier
+      return "builtin";
+    } else {
+      // Used as type
+      return "variable-3";
+    }
+  }
+
+  if (stream.match(builtins)) return "builtin";
+  if (stream.match(atoms)) return "atom";
+  if (stream.match(identifiers)) return "variable";
+
+  // other
+  if (stream.match(singleOperators)) return "operator";
+
+  // unrecognized
+  stream.next();
+  return null;
+};
+
+CodeMirror.defineMode("webidl", function() {
+  return {
+    startState: function() {
+      return {
+        // Is in multiline comment
+        inComment: false,
+        // Last non-whitespace, matched token
+        lastToken: "",
+        // Next token is a definition
+        startDef: false,
+        // Last token of the statement is a definition
+        endDef: false
+      };
+    },
+    token: function(stream, state) {
+      var style = readToken(stream, state);
+
+      if (style) {
+        var cur = stream.current();
+        state.lastToken = cur;
+        if (style === "keyword") {
+          state.startDef = startDefs.test(cur);
+          state.endDef = state.endDef || endDefs.test(cur);
+        } else {
+          state.startDef = false;
+        }
+      }
+
+      return style;
+    }
+  };
+});
+
+CodeMirror.defineMIME("text/x-webidl", "webidl");
+});