[MERGE] stable-2.15 to stable 2.16

['Brian Foley' via ganeti-devel]

commit ad83a3d144c18a7191b7852c01871b43e83b54bd
Merge: 24da2b1 55ad60e
Author: Brian Foley <bpfo...@google.com>
Date:   Thu Jul 7 11:31:19 2016 +0100

    Merge branch 'stable-2.15' into stable-2.16
    
    * stable-2.15
      Cleanup more pylint/pep8/apidoc errors
      KVM: handle gracefully too old/too new psutil versions
    
    Manually fix up merge conflicts.
    
    Signed-off-by: Brian Foley <bpfo...@google.com>