Merge the attribute map of ChannelHandlerContext into Channel

- Fixes #2136
[#2058] Use correct MANIFEST.MF file for source jars
Fix try to delete file while it does not exist anymore (see #2102 and #1713) in reference to this issue
Disable Javassist completely on Android

- Related: #2127
- Inspector warnings
SPDY example app
Make use of a Logger in the SPDY example and simplify it a bit
Make sure we not leak messages in the SPDY example
Add testcase to try to reproduce #2144
Fix fileChannel not closed, preventing delete to occur correctly
Add a log message on deletion failure
Run the autobahntestsuite as part of the testsuite
Increase permgen space for javadoc creation
Not throw an exception if subprotocol is not supported but just drop the header as stated in the RFC's
Fix API documentation on the usage of AttributeKey
Revert "Increase permgen space for javadoc creation"

This reverts commit 491b2fd69a25f746715f9d75940df9c96baa2404.
[#2161] Reduce the verbosity of the autobahntestsuite by eliminate the printed stacktraces
Add ReferenceCounted.touch() / Add missing retain() overrides

- Fixes #2163
- Inspector warnings
Touch a ReferenceCounted while it traverses across a pipeline
Fix inspector warnings
Enable a user specify an arbitrary information with ReferenceCounted.touch()

- Related: #2163
- Add ResourceLeakHint to allow a user to provide a meaningful information about the leak when touching it
- DefaultChannelHandlerContext now implements ResourceLeakHint to tell where the message is going.
- Cleaner resource leak report by excluding noisy stack trace elements