Build: Tweak getQunitData() regex to support alpha releases

We keep using getLatestStable() as before to only display stable
version on the CDN home page, but the subpage can include alpha
releases, same as we do for jQuery Mobile, for example.

Closes #106

Author: Krinkle

Gruntfile.js

@@ -64,6 +64,15 @@ grunt.registerTask( "build-index", function() {
 		} );
 	}
 
+	/**
+	 * @param {string[]} files
+	 * @param {RegExp} regex
+	 *  - Overall match: full path from /cdn/
+	 *  - Match [1]: (unused) overall match
+	 *  - Match [2]: semver version
+	 *  - Match [3] (optional) file extension prefix. If present, file is presumed redundant and skipped.
+	 * @return {Object[]}
+	 */
 	function parseReleases( files, regex ) {
 		return files
 			.map( function( filename ) {
@@ -303,8 +312,8 @@ grunt.registerTask( "build-index", function() {
 
 	function getQunitData() {
 		var files = grunt.file.expand( "cdn/qunit/*.js" ),
-			releases = parseStableReleases( files,
-				/(qunit\/qunit-(\d+\.\d+\.\d+[^.]*)(?:\.(min))?\.js)/ );
+			releases = parseReleases( files,
+				/(qunit\/qunit-(\d+\.\d+\.\d+(?:[A-z-]+\.\d+)?)(?:\.(min))?\.js)$/ );
 
 		releases.forEach( function( release ) {
 			release.theme = release.filename.replace( ".js", ".css" );