Happy 2014!
Update Travis configuration
Factor exceptions into exceptions.rb
Raise Celluloid::TimeoutError on mailbox timeout

Previously mailboxes would simply return nil upon timeout. This made it
difficult to disambiguate when timeouts occurred versus other events.

This changes mailboxes to raise a TimeoutError when timeouts occur.
Merge pull request #368 from celluloid/mailbox-timeout-exceptions

Raise Celluloid::TimeoutError on mailbox timeout
Replace case statements with class clauses with instance_of? checks. Fixes performance degredation due to module hierarchy traversal.
Merge pull request #370 from cheald/replace-module-case-with-instanceof

Replace case statements with class clauses with instance_of? checks.
Don't use null object as logger in tests

It seems that null objects don't handle `warn` properly, sometimes, or something. This was causing lots of stuff to be printed to stderr in celluloid-zmq's tests. It isn't really necessary to use a null object, we can simply make an assertion on the actual logger object. We've defined the logger to log to a special fine in the spec_helper anyway. This also removes the need to reset the logger in an around filter, which is nice.
Silence const redefinition warning by using a local variable for the class instead
Merge pull request #372 from jnicklas/one-logger-to-rule-them-all

Don't use null object as logger in tests
Merge pull request #373 from jnicklas/stfu

Silence const redefinition warning by using a local variable for the class instead
Make Mailbox#next_message private, closes #374

Calling #next_message without holding the mutex is unsafe. This method should not be part of Mailbox's public API.
Shut down mailbox after each example

This is needed for celluloid-zmq, since we want to be able to close the ZMQ context, which hangs if the Mailbox isn't shut down properly.
Prevent race condition in JRuby

JRuby is fast enough that sometimes the active thread manages to grab the same thread that the idle thread is using, which means the number of threads is not correct
We aren't using ThreadGroup anyway, are we?
Merge pull request #378 from jnicklas/jruby-stability

Jruby stability
Merge pull request #375 from jnicklas/private-next-message

Make Mailbox#next_message private, closes #374
Explain that TaskFiber backtraces are not available instead of just silently hiding them

See #379
Merge pull request #380 from celluloid/better_task_termination_stacktrace

Explain that TaskFiber backtraces are not available instead of just silently hiding them
Add LICENSE.txt to gem.files in gemspec