PHP v3 finished

I've gotten the vectors to work now, yay!  I also got rid of the pre-processing stuff and just made the test suite read directly from the vectors folder at runtime.

I also made it emulate the bug in Obj-C's v2 (and presumably v1?) by truncating multibyte passwords there.  And I added unit tests to verify this behavior, as well as to make sure they don't get truncated in v3.

Thanks Rob!