Support of JavascriptMVC EJS tags <%== and <%#

EJS parser in JavascriptMVC supports some special tags.
This PR adds supports for some of these.

 - for raw (unescaped) output you can use tag <%== output %>
   (for extracting strings it treats the same as <%= output %>)

 - adding comments with tag <%# Comment %>
   (for extracting strings it treats the same as the include statement:
   removes from temporary js content)

See: http://javascriptmvc.com/docs/can.EJS.html#section_MagicTags