Revert "Remove the Twisted adapter to get 0.9.6 out the door"

The Twisted adapter needs a few cosmetic changes, but otherwise works
fine. This reverts commit 982707dc1a2efd2544125d74a218d3f03390d521.
Fix the Twisted adapter to correctly function with current HEAD.
fixed -- Channel._shutdown was being called twice when there were
consumers which resulted in the following error from RabbitMQ:
`{amqp_error,channel_error,"expected 'channel.open'",'channel.close'}`.
RabbitMQ would then close the connection.
Address issue #261

Make sure Channel._cleanup is called when the channel is closed
Remove any lingering callbacks for a removed channel, rename an internal method variable
Address issue #257

- Missing the constraint parameter for the _on_return callback processing
Log when a prefix is being cleared from the callback stack
Prepare the 0.9.9 Release
fixed bug - connection.Connection.close wouldn't actually send
a close when there were channels with consumers due to a logic
error
Merge pull request #267 from atatsu/dbl_channel_close_fix

fixed channel.close and connection.close issues
Merge pull request #259 from wulczer/bring-back-twisted-adapter-203

Bring back the Twisted adapter
Fix timeout in twisted adapter

Both callLater and add_timeout accept number of seconds until timeout,
no need to substract current time.
removed call to cleanup from Channel._shutdown
Pass milliseconds to poll
Fix channel._on_close() without a method frame.

If a channel close is triggered by connection close which doesn't have a
method_frame (eg, because of a socket disconnection due to missed
heartbeats), channel._on_close() will be called with a method_frame of
None.  This patch handles this, to avoid looking up attributes on None.
Merge pull request #276 from rboulton/channel_onclose_fix

Fix channel._on_close() without a method frame.
Merge pull request #274 from cellscape/pass-ms-to-poll-268

Pass milliseconds to poll
Merge pull request #270 from cellscape/fix-twisted-add-timeout

Fix timeout in twisted adapter
Merge pull request #272 from atatsu/cleanup-breakage

removed call to cleanup from Channel._shutdown
Revert "fixed bug - connection.Connection.close wouldn't actually send"

This reverts commit 74929841c354516a62b176e3e1a67b467616c8d9.