removing validations for netvirt related testing

removing validations for netvirt related testing

- because the job that runs these suites is now only loading the ovsdb
  plugin, it is not valid to test anything to do with net-virt (e.g. br-int)
  or openflow (e.g. flow programming).  So, all checks/tests in those areas
  have been removed.

- this patch also introduces two new test cases per suite to check for
  bugs 4756 and 4794.

- other refactors include:
  *  marking karaf.log at the start of every test case
  *  using Force Tags, instead of the same tag in every test case
  *  migrating to new system variable names (e.g. ODL_SYSTEM_IP)

Change-Id: I47d53cbf36b82dd65111b6d7b7c9337cee07a07d
Signed-off-by: Jamo Luhrsen <jluhrsen@redhat.com>