Support for compliance checking testing

Updated to conformance generator to not generate tests with results for
compliance tests.
Updated test runner to run compliance mode version (precise & abs mode)
of reference model to create test results to use against SUT results.
Updated reference model to enable abs_mode on correct desc.json flags.
Updated test checker to support compliance checking using verifier lib.
Seperated color printing from test checker.

Change-Id: I7e2fbfc6883916caa5d94d4ece122c48bf45f530
Signed-off-by: Jeremy Johnson <jeremy.johnson@arm.com>