Bug 840012 - Fix test name. r=luke

--HG--
rename : js/src/jit-test/tests/basic/testBug0012.js => js/src/jit-test/tests/basic/testBug840012.js
Bug 847279 - Fix incorrect relativesrcdir in other mochitest makefiles. r=mbrubeck
Bug 847279 - Fix hardcoded path names in mochitests to match relativesrcdir. r=mbrubeck