LU-56 lnet: container for LNet message

LU-56 lnet: container for LNet message

Adding a simple message container to LNet, and use it to replace
global message queues and message finalizers.
It's a work step of LNet SMP improvements, we will create instances
for each CPT in following patches.

Signed-off-by: Liang Zhen <liang@whamcloud.com>
Change-Id: I00f79d7598c4cd1274d7b72f7c4b482d9df75b7a
Reviewed-on: http://review.whamcloud.com/2922
Reviewed-by: Bobi Jam <bobijam@whamcloud.com>
Reviewed-by: Doug Oucharek <doug@whamcloud.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>