Merge branch 'stable-2.7' into stable-2.8

Merge branch 'stable-2.7' into stable-2.8

* stable-2.7
  Fix documentation of gnt-instance batch-create
  Support multi instance allocs without iallocator
  Document --no-conflicts-check for gnt-network
  Check disk template in right dict when copying
  ganeti.backend_unittest: chmod restricted cmd dir
  Fix formatting of tuple in error message
  Fix 'prcre' typo in INSTALL
  Format gnt-network info group output
  Add 2.7.2 NEWS entry

Conflicts:
	INSTALL
      (trivial)
	NEWS
      (added entry to unreleased 2.8 section with remark that it was
       merged from 2.7)
	lib/cmdlib.py
      (followed cmdlib split)

Signed-off-by: Thomas Thrainer <thomasth@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>