Allow to pick mlocate.db from current directory
gitignore compile and test-driver
automatically enable openmp if available

For some speedup on multicore machines
updated to newer check library

We'll likely start failing on older version, but given it's just
tests, it seems fine.
Merge remote-tracking branch 'avsej/master'

* avsej/master:
  Allow to pick mlocate.db from current directory