rename play multi version test

+review REVIEW-5263
for quickTest builds, run only last version in multiversion tests
revert comment in build.gradle for platform builds
declare test sourceset and classes on playbinary
+review REVIEW-5263
split creation of run and of test related task in seperate mutation rules

+review REVIEW-5263
Google Test framework initial integration with Gradle. It includes
plugin, tests, docs and sample.