Bug 631842 (part 1) - Clone the PGO profile test script and data for use in the Valgrind test.  r=ted.

--HG--
rename : build/pgo/profileserver.py => build/valgrind/valgrind_test.py
extra : rebase_source : bef17f3e49e9e94883897dfb75a986cb10dc6105
Bug 631842 (part 2) - Implement |mach valgrind-test|.  r=gps.