Minor string freeze breakage in control-center

[Jody Goldberg <jody gnome org>]

One of the changes in 2.0.1 was for the keyboard capplet to switch
from an option menu to a slider.  I accidentally labeled the right
hand side of both sliders 'faster' this was 

1) wrong.  The delay was actually longer to the right
2) inconsistent with the mouse capplet, which uses Fast

I just committed a small change to use Fast/Slow and Short/Long

Apologies.