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/dtd/dtd.js

@@ -0,0 +1,142 @@
+// CodeMirror, copyright (c) by Marijn Haverbeke and others
+// Distributed under an MIT license: http://codemirror.net/LICENSE
+
+/*
+  DTD mode
+  Ported to CodeMirror by Peter Kroon <plakroon@gmail.com>
+  Report bugs/issues here: https://github.com/codemirror/CodeMirror/issues
+  GitHub: @peterkroon
+*/
+
+(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";
+
+CodeMirror.defineMode("dtd", function(config) {
+  var indentUnit = config.indentUnit, type;
+  function ret(style, tp) {type = tp; return style;}
+
+  function tokenBase(stream, state) {
+    var ch = stream.next();
+
+    if (ch == "<" && stream.eat("!") ) {
+      if (stream.eatWhile(/[\-]/)) {
+        state.tokenize = tokenSGMLComment;
+        return tokenSGMLComment(stream, state);
+      } else if (stream.eatWhile(/[\w]/)) return ret("keyword", "doindent");
+    } else if (ch == "<" && stream.eat("?")) { //xml declaration
+      state.tokenize = inBlock("meta", "?>");
+      return ret("meta", ch);
+    } else if (ch == "#" && stream.eatWhile(/[\w]/)) return ret("atom", "tag");
+    else if (ch == "|") return ret("keyword", "seperator");
+    else if (ch.match(/[\(\)\[\]\-\.,\+\?>]/)) return ret(null, ch);//if(ch === ">") return ret(null, "endtag"); else
+    else if (ch.match(/[\[\]]/)) return ret("rule", ch);
+    else if (ch == "\"" || ch == "'") {
+      state.tokenize = tokenString(ch);
+      return state.tokenize(stream, state);
+    } else if (stream.eatWhile(/[a-zA-Z\?\+\d]/)) {
+      var sc = stream.current();
+      if( sc.substr(sc.length-1,sc.length).match(/\?|\+/) !== null )stream.backUp(1);
+      return ret("tag", "tag");
+    } else if (ch == "%" || ch == "*" ) return ret("number", "number");
+    else {
+      stream.eatWhile(/[\w\\\-_%.{,]/);
+      return ret(null, null);
+    }
+  }
+
+  function tokenSGMLComment(stream, state) {
+    var dashes = 0, ch;
+    while ((ch = stream.next()) != null) {
+      if (dashes >= 2 && ch == ">") {
+        state.tokenize = tokenBase;
+        break;
+      }
+      dashes = (ch == "-") ? dashes + 1 : 0;
+    }
+    return ret("comment", "comment");
+  }
+
+  function tokenString(quote) {
+    return function(stream, state) {
+      var escaped = false, ch;
+      while ((ch = stream.next()) != null) {
+        if (ch == quote && !escaped) {
+          state.tokenize = tokenBase;
+          break;
+        }
+        escaped = !escaped && ch == "\\";
+      }
+      return ret("string", "tag");
+    };
+  }
+
+  function inBlock(style, terminator) {
+    return function(stream, state) {
+      while (!stream.eol()) {
+        if (stream.match(terminator)) {
+          state.tokenize = tokenBase;
+          break;
+        }
+        stream.next();
+      }
+      return style;
+    };
+  }
+
+  return {
+    startState: function(base) {
+      return {tokenize: tokenBase,
+              baseIndent: base || 0,
+              stack: []};
+    },
+
+    token: function(stream, state) {
+      if (stream.eatSpace()) return null;
+      var style = state.tokenize(stream, state);
+
+      var context = state.stack[state.stack.length-1];
+      if (stream.current() == "[" || type === "doindent" || type == "[") state.stack.push("rule");
+      else if (type === "endtag") state.stack[state.stack.length-1] = "endtag";
+      else if (stream.current() == "]" || type == "]" || (type == ">" && context == "rule")) state.stack.pop();
+      else if (type == "[") state.stack.push("[");
+      return style;
+    },
+
+    indent: function(state, textAfter) {
+      var n = state.stack.length;
+
+      if( textAfter.match(/\]\s+|\]/) )n=n-1;
+      else if(textAfter.substr(textAfter.length-1, textAfter.length) === ">"){
+        if(textAfter.substr(0,1) === "<") {}
+        else if( type == "doindent" && textAfter.length > 1 ) {}
+        else if( type == "doindent")n--;
+        else if( type == ">" && textAfter.length > 1) {}
+        else if( type == "tag" && textAfter !== ">") {}
+        else if( type == "tag" && state.stack[state.stack.length-1] == "rule")n--;
+        else if( type == "tag")n++;
+        else if( textAfter === ">" && state.stack[state.stack.length-1] == "rule" && type === ">")n--;
+        else if( textAfter === ">" && state.stack[state.stack.length-1] == "rule") {}
+        else if( textAfter.substr(0,1) !== "<" && textAfter.substr(0,1) === ">" )n=n-1;
+        else if( textAfter === ">") {}
+        else n=n-1;
+        //over rule them all
+        if(type == null || type == "]")n--;
+      }
+
+      return state.baseIndent + n * indentUnit;
+    },
+
+    electricChars: "]>"
+  };
+});
+
+CodeMirror.defineMIME("application/xml-dtd", "dtd");
+
+});