LU-6833 build: gerrit_checkpatch.py improvements

LU-6833 build: gerrit_checkpatch.py improvements

In contrib/scripts/gerrit_checkpatch.py:
  Add LASSERT and LCONSOLE, to the list of ignored types.
  Use a 60 second HTTP request timeout to avoid hangs.
  Catch any Exception around HTTP methods.
  Refactor some methods for to facilitate unit testing.
  Add timestamps to log messages.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: Ic8ddf815e58744af1cfa5a03986d869b790d91ae
Reviewed-on: http://review.whamcloud.com/15560
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>