[cadcdev-tiki] Key modifiers and repeating

[Sam S. <sam...@gm...>]

Since the notification emails aren't working, I'll post one myself :-P

I checked in some changes to hid that handle modifier keys (shift/ 
ctrl/alt) on SDL and OS X, as well as adding key repeating (KeyPress  
only, not KeyDown, just like OS X) to SDL.  I also fixed a typo in  
Time::sleep() for SDL that prevented it from working.

I should have the keyboard changes in for Win32 soon too.

-Sam