Correctly handle remove from epoll and EPOLLRDHUP. Also fix a bug with removing EPOLLIN and EPOLLOUT
HttpObjectDecoder.invalidChunk() should return LastHttpChunk

because the decoder will enter 'BAD_MESSAGE' state and will not produce any chunk since then.
Ensure that the last bad chunk is LastHttpChunk
Fix a bug where HttpObjectAggregator doesn't always produce FullHttpMessage

- Fixes #2182
- Always convert an unfull invalid message to a full message
Fix a regression which could lead to GenericFutureListeners never been notifed. Part of [#2186].

This regression was introduced by commit c97f2d2de00ad74835067cb6f5a62cd4651d1161
Expose a callback in HttpObjectAggregator to handle oversized messages

- Related: #2211
Overall clean-up of HttpObjectAggregator / Handle oversized response differently

- Related: #2211
Remove the deprecated constant field

Exposing the constant as a public static final field is usually not a
good idea because it gives less flexibility to us when we happen to
change our internal implementation.
Added a test for oversized HTTP responses
Add an operation that resets the state of HttpObjectDecoder

Motivation:

Currently, it is impossible to give a user the full control over what to do in response to the request with 'Expect: 100-continue' header.  Currently, a user have to do one of the following:

- Accept the request and respond with 100 Continue, or
- Send the reject response and close the connection.

.. which means it is impossible to send the reject response and keep the connection alive so that the client sends additional requests.

Modification:

Added a public method called 'reset()' to HttpObjectDecoder so that a user can reset the state of the decoder easily.  Once called, the decoder will assume the next input will be the beginning of a new request.

HttpObjectAggregator now calls `reset()`right after calling 'handleOversizedMessage()' so that the decoder can continue to decode the subsequent request even after the request with 'Expect: 100-continue' header is rejected.

Added relevant unit tests / Minor clean-up

Result:

This commit completes the fix of #2211
Fix a memory leak in HttpObjectAggregatorTest
Fix another leak in HttpObjectAggregatorTest by removing redundant code
SPDY: remove SPDY/3 support