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/slim/test.js

@@ -0,0 +1,96 @@
+// CodeMirror, copyright (c) by Marijn Haverbeke and others
+// Distributed under an MIT license: http://codemirror.net/LICENSE
+
+// Slim Highlighting for CodeMirror copyright (c) HicknHack Software Gmbh
+
+(function() {
+  var mode = CodeMirror.getMode({tabSize: 4, indentUnit: 2}, "slim");
+  function MT(name) { test.mode(name, mode, Array.prototype.slice.call(arguments, 1)); }
+
+  // Requires at least one media query
+  MT("elementName",
+     "[tag h1] Hey There");
+
+  MT("oneElementPerLine",
+     "[tag h1] Hey There .h2");
+
+  MT("idShortcut",
+     "[attribute&def #test] Hey There");
+
+  MT("tagWithIdShortcuts",
+     "[tag h1][attribute&def #test] Hey There");
+
+  MT("classShortcut",
+     "[attribute&qualifier .hello] Hey There");
+
+  MT("tagWithIdAndClassShortcuts",
+     "[tag h1][attribute&def #test][attribute&qualifier .hello] Hey There");
+
+  MT("docType",
+     "[keyword doctype] xml");
+
+  MT("comment",
+     "[comment / Hello WORLD]");
+
+  MT("notComment",
+     "[tag h1] This is not a / comment ");
+
+  MT("attributes",
+     "[tag a]([attribute title]=[string \"test\"]) [attribute href]=[string \"link\"]}");
+
+  MT("multiLineAttributes",
+     "[tag a]([attribute title]=[string \"test\"]",
+     "  ) [attribute href]=[string \"link\"]}");
+
+  MT("htmlCode",
+     "[tag&bracket <][tag h1][tag&bracket >]Title[tag&bracket </][tag h1][tag&bracket >]");
+
+  MT("rubyBlock",
+     "[operator&special =][variable-2 @item]");
+
+  MT("selectorRubyBlock",
+     "[tag a][attribute&qualifier .test][operator&special =] [variable-2 @item]");
+
+  MT("nestedRubyBlock",
+      "[tag a]",
+      "  [operator&special =][variable puts] [string \"test\"]");
+
+  MT("multilinePlaintext",
+      "[tag p]",
+      "  | Hello,",
+      "    World");
+
+  MT("multilineRuby",
+      "[tag p]",
+      "  [comment /# this is a comment]",
+      "     [comment and this is a comment too]",
+      "  | Date/Time",
+      "  [operator&special -] [variable now] [operator =] [tag DateTime][operator .][property now]",
+      "  [tag strong][operator&special =] [variable now]",
+      "  [operator&special -] [keyword if] [variable now] [operator >] [tag DateTime][operator .][property parse]([string \"December 31, 2006\"])",
+      "     [operator&special =][string \"Happy\"]",
+      "     [operator&special =][string \"Belated\"]",
+      "     [operator&special =][string \"Birthday\"]");
+
+  MT("multilineComment",
+      "[comment /]",
+      "  [comment Multiline]",
+      "  [comment Comment]");
+
+  MT("hamlAfterRubyTag",
+    "[attribute&qualifier .block]",
+    "  [tag strong][operator&special =] [variable now]",
+    "  [attribute&qualifier .test]",
+    "     [operator&special =][variable now]",
+    "  [attribute&qualifier .right]");
+
+  MT("stretchedRuby",
+     "[operator&special =] [variable puts] [string \"Hello\"],",
+     "   [string \"World\"]");
+
+  MT("interpolationInHashAttribute",
+     "[tag div]{[attribute id] = [string \"]#{[variable test]}[string _]#{[variable ting]}[string \"]} test");
+
+  MT("interpolationInHTMLAttribute",
+     "[tag div]([attribute title]=[string \"]#{[variable test]}[string _]#{[variable ting]()}[string \"]) Test");
+})();