[MERGE] stable-2.14 to stable 2.15

['Brian Foley' via ganeti-devel]

commit fd4c2bf9e0ff3fda83dbea9ef30501085588aa4a
Merge: 55ad60e 7e47c36
Author: Brian Foley <bpfo...@google.com>
Date:   Mon Aug 22 11:59:42 2016 +0100

    Merge branch 'stable-2.14' into stable-2.15
    
    * stable-2.13
      Bugfix: migrate needs HypervisorClass, not an instance
    
    Signed-off-by: Brian Foley <bpfo...@google.com>