Merge branch 'devel-2.7'

* devel-2.7: (23 commits)
  QA: Support additional arguments for initialization
  qa_utils: Fix order of arguments passed to _AssertRetCode
  Improve reporting on errors.AddressPoolError exceptions
  Add note about lv-tags rename
  Make use of HooksDict() for networks
  Remove family and size from network objects
  Remove network_type slot (Issue 363)
  Moved uniformity check for exclusive_storage flag
  "exclusive_storage" cannot be changed on single nodes
  Upgrades made on loading the configuration are always saved
  Show correct daemon name on Luxi connect errors
  Update the security document for Ganeti 2.7
  OS environment: add network information
  ConfigData: run UpgradeConfig on network objects
  Make ParticalNic's network field of type String
  Make gnt-os list work with no OSes
  Fix OCF files installation in devel/upload
  baserlib: Fix two mistakes in docstring
  Workaround hlint behaviour with no warnings/errors
  Remove use of 'head' and add hlint warning for it
  ...

Conflicts:
	qa/qa_cluster.py: Trivial
	qa/qa_node.py: Node attributes
	src/Ganeti/Types.hs: Network cleanup
	test/hs/Test/Ganeti/Objects.hs: Network cleanup

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Bernardo Dal Seno <bdalseno@google.com>