[#1442] Make sure closing the channel will not cause an UnsupportedOperationException
Deprecate NoSuchBufferException as it's not used anymore
Javadocs cleanup
Deprecate IncompleteFlushException as its not used anymore
More javadoc fixes
Make sure the exception is thrown when it happens during test
Remove unused exception classes
Fix memory leak
Revert "[#1442] Make sure closing the channel will not cause an UnsupportedOperationException"

This reverts commit a1a86b9de48e4696e3496904dd972336f57b4a0b because the
semantic of ctx.isRemoved() is confusing to a user - why is
ctx.isRemoved() false when handlerRemoved() is invoked? A better
solution would be check if the connection is inactive and mark the
promise as failure before attempting to write anything.
Make sure writing to a closed channel does not trigger an UnsupportedOperationException

- Fixes #1442
Determine the default number of heap/direct arenas of PooledByteBufAllocator conservatively

- Fixes #1445
- Add PlatformDependent.maxDirectMemory()
- Ensure the default number or arenas is decreased if the max memory of the VM is not large enough.
[maven-release-plugin] prepare release netty-4.0.0.CR5
[maven-release-plugin] prepare for next development iteration
Don't release messages before throw UnsupportedOperationException, as the caller method will take care
Introduce new utility class calles ReferenceCountUtil and move utility methods from ByteBufUtil to it.

The ones in ByteBufUtil were marked as @deprecated
[#1448] Don't print failure if VoidChannelPromise is used
[#1450] Fix examples in ReplayDecoder javadocs
SPDY: better encapsulation of header encoding/decoding
SCTP: Reduce object allocation overhead and fix receive buffer allocation

There are a couple of changes here all related to making the SCTP
transport less garbage-heavy:

- Remove the SctpNotificationEvent and just passes along the JDK NIO
  Notification, as passing the Notification and always null inside a
  wrapped object seemed a little bit superfluous
- Apply @trustin's changes to receive buffer allocation to SCTP
  transport, and also makes the SCTP transport use the configured buffer
  allocator rather than always creating a direct buffer (which seems
  like a bug)
Upgrade to javassist 3.18.0-GA