[Cdash] Emma coverage

[Nils Gladitz]

I am manually collecting java emma coverage during one of our project 
test runs and saw that CDash now also supports analysing emma coverage.

Can anyone elaborate how this works?

I assume part of it is CMake's new ctest_submit(CDASH_UPLOAD)?

Looking at the CDash changes it seems to expect a tar file with json 
files in it.

Emma seems to be able to generate (summarizing) reports in txt, html and 
xml. The metadata (coverage.em) and runtime coverage (coverage.ec) input 
files look binary.

How are the expected json files generated?

Nils