64bit inline asm

Add 64bit asm code for Linux and Darwin to the functions that already
have darwin32 code.
A quick little fix or this #if won't work correctly
Sligth modifications as per suggestions from breznak
Unify linux64 and darwin64 cpuid

Shouldn't have been saving the id directly to a memory location.
Merge remote branch 'upstream/master' into 64bit-asm
Merge remote branch 'upstream/master' into 64bit-asm
Merge pull request #94 from wilsonk/64bit-asm

64bit asm