RCBC-27 EventMachine plugin

Introduce plugin which allows to use EventMachine as event loop for
couchbase client.

With Ruby 1.9 and Fibers it is possible to use blocking interface,
otherwise connection should be asynchronouse and connection.run should not
be used.

Change-Id: I6a5bd7c86f9ce5f3b7090b0c58bc411d6b6a52f7
Reviewed-on: http://review.couchbase.org/23347
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Add simple chat based on EventMachine with Couchbase logger

Change-Id: If0a80f31d87ba632ff6510e2175c340dfcc876ba
Reviewed-on: http://review.couchbase.org/24480
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Fix mingw build. It does support only native plugin via libcouchbase

Change-Id: Ief0ec2480e3e6c1507ff1b8fd70b2812a8cfccd6
Reviewed-on: http://review.couchbase.org/24503
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Bump version 1.2.2

Change-Id: Ibf7f3c63dba3f8c61ac9f28c5da1a9a711918749
Reviewed-on: http://review.couchbase.org/24504
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Matt Ingenthron <matt@couchbase.com>
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>