POSIX message queues allow local processes to exchange data in the form
of messages. This API is distinct from that provided by System V
message queues, but provides similar functionality.

* http://bogomips.org/ruby_posix_mq/
* ruby.posix.mq@librelist.com />* git://git.bogomips.org/ruby_posix_mq.git

Changes:

Rubinius 1.2 as well as Ruby 1.9. Ruby 1.8 works except it will
block the entire interpreter for blocking operations. Spurious
errors during GC for POSIX_MQ#to_io users are now avoided.