- fixed not used HLSL settings from <custom>.ini if MAME was started
without driver parameter
- removed default values from HLSL sliders, the defaults here are more
like null values to hint when an effect would be disable
- slightly changed default HLSL settings
- screen adjustment (scale, offset) can now be handled by the respective
render API itself (default behavior is as before)
- D3D (if HLSL) is activated handles screen adjustment by itself within
the shader, which fixes the odd behavior of some effects (e.g. round
corners) when screen scale and offset is used
- added special post.fx and distortion.fx shader, which support enabled
artworks, but they cannot apply some of the previously implemented
corrections (e.g. bloom staircase artifacts when screen is curved,
elliptic rounded corners when aspect ratio is not 4:3)
