emu.speedmode

[GoogleCodeExporter]

Add emu.speedmode to the Lua implementation. Presumably would be the same 
concept as it is in FCEUX:

emu.speedmode(string mode)

Set the emulator to given speed. The mode argument can be one of these:
       - "normal"
       - "nothrottle" (same as turbo on fceux)
       - "turbo"
       - "maximum"

Original issue reported on code.google.com by brandman...@gmail.com on 12 May 2012 at 5:28