Turned on the TCP_NODELAY socket option (disables Nagle's algorithm)

Tests show an 8-20 fold improvement in throughput. Messages under 1500 total
bytes benefit the most. Even with messages of 10K in size there's still a 30%
improvement in throughput; that's a lot. Tested with JRuby 1.7.3 and Ruby EE
1.9.3 on RHEL 6.1 against ActiveMQ 5.8.0 (also running on RHEL 6.1).

Default is true, but can TCP_NODELAY can be turned off by putting :tcp_nodelay
=> false in the parameters hash.

(ppaul/6540400, #8)
Bugfixes for TCP_NODELAY commit.
Added a NullLogger, made it the default.

This lets us remove several instances of `if @logger &&
@logger.respond_to?(:some_method)`

(https://gist.github.com/ppaul/6540400, #9)
Merge pull request #76 from ismith/tcp_nodelay

Turned on the TCP_NODELAY socket option (disables Nagle's algorithm)
Add marshalling methods to Slogger.
Added Stomp::Errors::StartTimeoutException
Merge branch 'null_logger' into dev

Conflicts:
	lib/stomp/client.rb
Issue #78
ERROR frame handling.

The handler will raise an exception in the thread that has the Stomp::Client
object on receipt of ERROR frames.

(ppaul/6540400, #3)