Backport HBASE-4105 (Stargate does not support Content-Type: application/json and Content-Encoding: gzip in parallel)

When:
curl -H "Accept: application/json" http://localhost:3000/version -v

Response is:

• About to connect() to localhost port 3000 (#0)
• Trying 127.0.0.1... connected
• Connected to localhost (127.0.0.1) port 3000 (#0)
  > GET /version HTTP/1.1
  > User-Agent: curl/7.19.7 (universal-apple-darwin10.0) libcurl/7.19.7 OpenSSL/0.9.8r zlib/1.2.3
  > Host: localhost:3000
  > Accept: application/json
  >
  < HTTP/1.1 200 OK
  < Cache-Control: no-cache
  < Content-Type: application/json
  < Transfer-Encoding: chunked
  <
• Connection #0 to host localhost left intact
• Closing connection #0 {"Server":"jetty/6.1.26","REST":"0.0.2","OS":"Linux 2.6.32-bpo.5-amd64 amd64","Jersey":"1.4","JVM":"Sun Microsystems Inc. 1.6.0_22-17.1-b03"}

but with compression:
curl -H "Accept: application/json" http://localhost:3000/version -v --compressed

Reponse is:

• About to connect() to localhost port 3000 (#0)
• Trying 127.0.0.1 ... connected
• Connected to localhost (127.0.0.1) port 3000 (#0)
  > GET /version HTTP/1.1
  > User-Agent: curl/7.19.7 (universal-apple-darwin10.0) libcurl/7.19.7 OpenSSL/0.9.8r zlib/1.2.3
  > Host: localhost:3000
  > Accept-Encoding: deflate, gzip
  > Accept: application/json
  >
  < HTTP/1.1 200 OK
  < Cache-Control: no-cache
  < Content-Type: application/json
  < Content-Encoding: gzip
  < Transfer-Encoding: chunked
  <
• Connection #0 to host localhost left intact
• Closing connection #0

and the stargate server throws the following exception:

11/07/14 11:21:44 ERROR mortbay.log: /version
java.lang.ClassCastException: org.mortbay.jetty.HttpConnection$Output cannot be cast to org.apache.hadoop.hbase.rest.filter.GZIPResponseStream
at org.apache.hadoop.hbase.rest.filter.GzipFilter.doFilter(GzipFilter.java:54)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:399)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:928)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:549)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.jetty.bio.SocketConnector$Connection.run(SocketConnector.java:228)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

This is not reproduceable with content type text/plain and gzip.

This is somehow related to https://issues.apache.org/jira/browse/HBASE-3275