[MERGE] stable-2.15 to stable 2.16

['Brian Foley' via ganeti-devel]

commit e08fb1113fbf918096edab60b0fc6f666e3b35e6
Merge: 750467a 3b0794a
Author: Brian Foley <bpfo...@google.com>
Date:   Tue Apr 12 16:09:56 2016 +0100

    Merge branch 'stable-2.15' into stable-2.16
    
    * stable-2.15
      Update misleading comment in noded RPC code
      Fix ganeti-rapi/noded exit-under-load bug
      Remove extremely frequent debug logging message
      Fix ClusterVerifyConfig() causing high mem usage
      Use threaded runtime when linking Haskell unit tests
      Give JQueue test dirs unique prefixes so they can't conflict
      Fix hlint errors
      Fix pylint errors
      Update Hlint rules
      Hide TH "Loading package" messages when compiling GHC <7.10
    
    Manually fixup merge conflicts.
    
    Signed-off-by: Brian Foley <bpfo...@google.com>