Simplify boolean toggling in the TASInputDlg.

Also fixed the indentation for some code in a switch statement.
Fix a typo in DSPSymbols. (DisasssembleRange -> DisassembleRange)

Also remove IsHexDigit and IsAlpha and replace them with their cctype equivalents.
Merge pull request #163 from lioncash/dsp-func-typo

Fix a typo in DSPSymbols. (DisasssembleRange -> DisassembleRange)
Merge pull request #162 from lioncash/tas-dlg

Simplify boolean toggling in the TASInputDlg.
OGL: Remove some dead code.
OGL: Force highp for integers.
PixelShaderGen: Make SampleTexture static inline.
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.
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.
PixelShaderGen: Use integer math for TEV combiners.
PixelShaderGen: Remove superfluous registerstate stuff. Also, made alphabump an integer.
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.