Upgrade Caja to r4135 (issue1714043)

[jo...@gmail.com]

Reviewers: dev-remailer_shindig.apache.org, jasvir,

Description:
This change pulls in Caja updates that are relevant to Shindig in two
ways:

1. DefaultGadgetRewriter class API has changed from accepting a
PluginEnvironment to the pair of UriFetcher and UriPolicy.
   - Previous implementation modified to adapt to the new interfaces.

2. Several parser improvements now enable nearly all HTML parsing tests
to succeed, esp. social data-related tests.
   - Caja's parser now compatible w/ os templates and data pipelining!
   - Only remaining test fails since Caja's parser eats a DOMException
and turns it into a Warning. Will talk w/ Caja to assess best approach.

Please review this at http://codereview.appspot.com/1714043/show

Affected files:
    
java/gadgets/src/main/java/org/apache/shindig/gadgets/parse/caja/CajaHtmlParser.java
    
java/gadgets/src/main/java/org/apache/shindig/gadgets/servlet/CajaContentRewriter.java
    
java/gadgets/src/test/java/org/apache/shindig/gadgets/parse/AbstractParsingTestBase.java
    
java/gadgets/src/test/java/org/apache/shindig/gadgets/parse/caja/CajaSocialMarkupHtmlParserTest.java
   pom.xml