Update the Readme.md with suggestions and improvements by neobrain.

Updated the "Project Site" link to point to the github page. Also added links to the forums and wiki. Also fixed some list indentation in the system requirements.
Move the recommended CPU/GPU sentences onto their own indented line in the system requirements list (thanks go to neobrain for pointing this out).
Add a period in the system requirements list for consistency.
Merge pull request #6 from lioncash/readme-markdown

Change the plain-text Readme.txt to a markdown-using Readme.md.
OGL: Force highp for integers.
PixelShaderGen: Make SampleTexture static inline.
PixelShaderGen: Use integer math for alpha testing.
PixelShaderGen: Fix an issue where small negative z coordinates would underflow when they shouldn't.
PixelShaderGen: Use integer math for sampling textures.
PixelShaderGen: Use integer math for indirect texture coords.
PixelShaderGen: Use integer math for rasterizer color.
PixelShaderGen: Remove remaining floating point bits for texture color.
PixelShaderGen: Use integer math for tev konst value.
PixelShaderGen: Use integer math for tev outputs. Seems like things are temporarily broken.
PixelShaderGen: Use integer math for TEV combiners. Things are still broken.
PixelShaderGen: Remove superfluous registerstate stuff. Also, made alphabump an integer. Things are working again!
PixelShaderGen: prev should be initialized to the proper value; tev output needs to be clamped between -1024 and 1023.
PixelShaderGen: Use integer math for indirect tev stage texcoord calculation.
PixelShaderGen: Microsoft's shader compiler likes to throw an internal error when masking with unsigned integers, so just use 255 instead of 0xFF all over the place...
Provide our own dot functions in GLSL since GLSL doesn't provide integer versions of this function, even though AMD and Nvidia provide their own.