we had a few ways versions of looking for support before executing a test. this
commit unifies them as well as add the check for all tests that previously
lacked them. found by running `./configure --without-ssl && make test`. also,
produce tap skip output if the test is skipped.
PR-URL: https://github.com/iojs/io.js/pull/1049
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Shigeki Ohtsu <ohtsu@iij.ad.jp>