pthread: pthread_barrier should call yield
tests: clean up test_pthread_barrier Makefile
Merge pull request #1562 from Kijewski/the-first-two-commits-of-the-branch-issue-198

posix: minor pthread_barrier clean up
tests: enable cppcheck for PR in travis
SQASHME: move to script
SQUASHME: unify files to check
SQUASHME: make it possible to pass options