Fix SPDY method header definition
Fix valid-message logic
Optimize SlicedByteBuf a little bit
Make same correction of getStatus -> status header
SpdySessionHandler doesn't have an inbound buffer

Check that it does have a buffer before trying to free.

This is probably unnecessarily defensive.
Coding style fix
[#1101] Fix NPE which accour when send a 100-continue response and using the HttpContentDecoder
[#1101] Fix NPE which accour when send a 100-continue response and using the HttpContentEncoder
[#1100 ] Fix SPDY codec to work again in 4.x
Merge branch 'upstream'

Conflicts:
	codec-http/src/main/java/io/netty/handler/codec/spdy/SpdySessionHandler.java