[#1943] Unpooled.copiedBuffer(ByteBuf pooled) should always return unpooled ByteBuf
[#1812] Allow for inline for most common cases when use NioByteUnsafe.read()
[#1812] Rework ByteToMessageDecoder.channelRead(..) method to allow for inlining
Revert "[#1812] Rework ByteToMessageDecoder.channelRead(..) method to allow for inlining"

This reverts commit b7262ab3da124f4d2db297e33c117ebff6cf1964.
[#1812] Rework ByteToMessageDecoder.channelRead(..) method to allow for inlining
Make all mutable fields in WebSocketClientHandshaker volatile

- Fixes #1945
[#1947] Handle RejectExecutionException graceful for outbound operations
Replace UniqueName with Constant and ConstantPool

- Proposed fix for #1824

UniqueName and its subtypes do not allow getting the previously registered instance.  For example, let's assume that a user is running his/her application in an OSGi container with Netty bundles and his server bundle.  Whenever the server bundle is reloaded, the server will try to create a new AttributeKey instance with the same name.  However, Netty bundles were not reloaded at all, so AttributeKey will complain that the name is taken already (by the previously loaded bundle.)

To fix this problem:

- Replaced UniqueName with Constant, AbstractConstant, and ConstantPool.  Better name and better design.

- Sctp/Udt/RxtxChannelOption is not a ChannelOption anymore.  They are just constant providers and ChannelOption is final now.  It's because caching anything that's from outside of netty-transport will lead to ClassCastException on reload, because ChannelOption's constant pool will keep all option objects for reuse.

- Signal implements Constant because we can't ensure its uniqueness anymore by relying on the exception raised by UniqueName's constructor.
Add a shortcut method for collision-free naming
[#1812] All to have NioMessageUnsafe.read() inlined
Run the Autobahn Testsuite as part of our testsuite. This ensures there are no regressions.
Use other port for testsuite
Revert usage of autobahntestsuite until figure out why it fails on CI
[#1959] Proposed fix to correctly handle timeouts that overflow the ticks in the wheel
[#1958] Use CRC32-C in Snappy as per the spec
Create StringBuilder with saner initial capacity when encoding a Cookie

Fixes #1951
Instead of complicated capacity estimation, just use thread local buffers.

Fixes #1951
Rename SimpleChannelInboundHandler.channelRead0() to messageReceived()

- Related: #1590
Allow a user to define his/her own length field decoder

- Fixes #1960
Also pass the ByteOrder in getUnadjustedFrameLength method. Part of #1960