Emulator

Hello,
I've decided to help progress the video plugin by turning on the
notification on shader compilation errors. On LoZ:WW, I was showered with
the same error message "Invalid subscript 'a'". Turns out that the
generator has, in addition to registers, a "0.0" value. You compile it in
most cases as a regular register, providing DX with, for example "0.0.a"
and "0.0.r".

Attached here is the patched PixelShader.cpp
(Source/Plugins/Plugin_VideoDX9/Src/PixelShader.cpp)

I hope it solves some stuff. After all, I've been testing LoZ:WW for quite
some time and there were no shader compilation errors whatsoever.

A nice addition would be more debug printouts(message boxes) to the video
plugin