RBD code merged into master

[Wido den Hollander <wi...@widodh.nl>]

Hi,

With the pending change from Edison coming up for moving all the KVM 
code into the plugins directory I merged in the RBD code.

It shouldn't break anything, but be reminded that the storage_pool table 
gets an extra field "user_info"

`user_info` varchar(255) NULL COMMENT 'Authorization information for the 
storage pool. Used by network filesystems',

I'll make sure this gets into the 3.X -> 4.0 upgrade scripts.

If you manually want to adjust your table:

ALTER TABLE `storage_pool` ADD `user_info` VARCHAR( 255 ) NULL COMMENT 
'Authorization information for the storage pool. Used by network 
filesystems' AFTER `host_address` ;

I'll keep working on this code so that we have a stable RBD integration 
for the 4.0 release.

Wido