AccelServlet should pass through all headers including caching headers

So far, the AccelServlet was designed to be only used for cache-control = public responses.
As a result, for private responses, Cache-Control headers are modified. For example, Cache-Control=private,max-age=100 is transformed to Cache-Control=no-cache. Also, other Cache-Control derivatives(such as must-revalidate, no-store etc) were stripped. For public content with neither a max-age or an Expires header, it set the max-age to a default ttl of 300secs.
This change simply passes through headers without modifying them.

Note that this change is dependent on http://codereview.appspot.com/4260059/

[gagan.goku, 2011-03-10 14:50:47]

LGTM++
Please send out to dev@

http://codereview.appspot.com/4271041/diff/1/java/gadgets/src/test/java/org/a...
File
java/gadgets/src/test/java/org/apache/shindig/gadgets/servlet/HtmlAccelServletTest.java
(right):

http://codereview.appspot.com/4271041/diff/1/java/gadgets/src/test/java/org/a...
java/gadgets/src/test/java/org/apache/shindig/gadgets/servlet/HtmlAccelServletTest.java:360:
.setHeader("Content-Type", "text/html")
Set Content-Type as part of headersMap as  well ?

[nikhilmadan23, 2011-03-10 15:21:01]

http://codereview.appspot.com/4271041/diff/1/java/gadgets/src/test/java/org/a...
File
java/gadgets/src/test/java/org/apache/shindig/gadgets/servlet/HtmlAccelServletTest.java
(right):

http://codereview.appspot.com/4271041/diff/1/java/gadgets/src/test/java/org/a...
java/gadgets/src/test/java/org/apache/shindig/gadgets/servlet/HtmlAccelServletTest.java:360:
.setHeader("Content-Type", "text/html")
On 2011/03/10 14:50:47, gagan.goku wrote:
> Set Content-Type as part of headersMap as  well ?

This is actually modified in AccelHandler(an additional UTF-8) gets appended to
the header value

[anupama.dutta, 2011-03-10 15:52:38]

LGTM.

[gagan.goku, 2011-03-10 19:20:55]

Build looks good.
Committed as r1080324.