Emulate GameCube memory card speeds

Fixes http://code.google.com/p/dolphin-emu/issues/detail?id=2284

Attempts to emulate GameCube memory card transfer speeds.

Wind Waker J has been tested and confirmed working with this by JMC47
Synthetic timing, as said in comment it's based on gameplay from GameCube videos I have found and starting save the same time they do in the video and attempting to match it up across a few games, which happened to apparently be accurate in other games that I did not test.