Adding capability in accel servlet to act as accelerating proxy (issue1712043)

[gagan . goku]

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

Message:
Please review.
Description:
- Adding accel servlet as catch all servlet
- Modifying AccelUriManager to deal with all urls.


Please review this at http://codereview.appspot.com/1712043/show

Affected files:
  M      
java/gadgets/src/main/java/org/apache/shindig/gadgets/servlet/AccelHandler.java
  M      
java/gadgets/src/main/java/org/apache/shindig/gadgets/uri/AccelUriManager.java
  M      
java/gadgets/src/main/java/org/apache/shindig/gadgets/uri/DefaultProxyUriManager.java
  M      
java/gadgets/src/test/java/org/apache/shindig/gadgets/servlet/HtmlAccelServletTest.java
  M     java/server/src/main/webapp/WEB-INF/web.xml