v0.6.0

This release includes a number of bugfixes and performance enhancements

lcm-c:

• Change internal buffering from a fixed size ringbuffer to
  per-subscription FIFO queues. Subscriptions start with a default maximum
  queue length of 30 messages, which can be adjusted using the new function
  <message_type>_subscription_set_queue_capacity()
  For example, to set the queue size to 5 for a message type example_t:
  example_t_subscription_t* subs =
  example_t_subscribe(lcm, "EXAMPLE", message_handler);
  example_t_subscription_set_queue_capacity(subs, 5);
• Explicitly disallow recursive calls to lcm_handle.
• fix synchronization issues when allocating receive resources and
  conducting multicast self-test. see issue #30

lcm-logplayer-gui:

• expose remote log player play and pause commands

lcm-logger:

• bugfix when creating subdirectories for output files

lcm-spy:

• bugfix when LCM URLs contain equal signs
• searches directories on classpath for lcmtype .class files, in
  addition to .jar files.

lcm-gen:
Python
- bugfix. remove extraneous typename
- Constructor initializes valid fixed-size arrays
- python initialize float, double to 0.0 instead of 0

Java
- emit_java now appends 'f' for const float

General:
- flush stdout before failing on parse / semantic error

General:
- add example for using LCM with GLib event loop
- add example program for using LCM with select()
- minor updates to API documentation