Cleaning up HtmlAccelServlet (issue1798042)

[gagan . goku]

Reviewers: johnfargo, zhoresh, cool-shindig-committers_googlegroups.com,  
shindig.remailer_gmail.com, dev-remailer_shindig.apache.org,


Please review this at http://codereview.appspot.com/1798042/show

Affected files:
  main/java/org/apache/shindig/gadgets/DefaultGadgetSpecFactory.java
  main/java/org/apache/shindig/gadgets/render/GadgetRewritersProvider.java
  main/java/org/apache/shindig/gadgets/servlet/HtmlAccelServlet.java
  test/java/org/apache/shindig/gadgets/render/HtmlRendererTest.java
  test/java/org/apache/shindig/gadgets/servlet/HtmlAccelServletTest.java