Improving Frontend Test Framework

The TestFileParser is enhanced to directly report errors
on malformed input data rather than simply ignoring the test. Until
now this could lead to a case where a malformed section will lead
to an ignored test when both PLAN and DISTRIBUTEDPLAN sections were empty.

Change-Id: Icc55fcbd02f887332d0383b3ab19fd072fe39ab2
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/4895
Tested-by: jenkins
Reviewed-by: Martin Grund <mgrund@cloudera.com>