[Cdash] Excluding sources from GcovTar coverage

[Nils Gladitz]

I am looking into replacing ctest_coverage() with CMake's new 
CTestCoverageCollectGCOV module and CDash's new GcovTar coverage support.

Is there an existing way to reproduce what ctest_coverage() did with 
CTEST_CUSTOM_COVERAGE_EXCLUDE?

If there isn't, where would be the best place to implement something 
like it?

e.g should CTestCoverageCollectGCOV exclude coverage files from the tar 
or should CDash ignore them?

For the later case how would one inform CDash about the inclusion? An 
additional/existing json configuration file in the tar?

Nils