Fix forking problem when running individual tests
The script now preloads all of the tests for all of the specified frameworks (every test is retrieved with --all). Then we fork of threads, bucketing as necessary to keep things sane. This is instead of forking of a thread per framework and then more threads for the tests of each framework where we could get up to 1000+ instances of HHVM going (and that is bad).
Also fixed a bug on how we retrieve the actual tests.
Did a little more refactoring too.
Singled out two tests from zf2 that was causing some weird deadlocking. Don't run those. Figure out why and then take them out.
Reviewed By: @ptarjan
Differential Revision:
D1037105