stabilize firefox test runner to use cfx run.
Some tests, namely rtcpeerconnection, oauth, and social-double (less so) are failing/flaky
Merge branch 'master' of github.com:freedomjs/freedom-for-firefox into willscott-stabilize
update readme
remove comment
add 'stayOpen' option to allow debugging after tests have run.
Merge pull request #28 from freedomjs/willscott-stabilize

stabilize firefox test runner to use cfx run.