Merge pull request #21 in SNORT/snort3 from coverage to master

* commit '3fe0b81e57bdbbbeea5f362de4929f4cd17bc1d0':
  separate piglet, check, and catch tests; add catch  tests for sfrim
  clean up rule index map handling; eliminate bogus code path; delete unused print function; simplify interface; free after parsing; also fix dev guide builds from top_srcdir