* render/bgfx: Improved clearing and blending. Added prescale support. Fixes MT07586, MT07587, MT08084.
* render/bgfx: Fixed blend and tint handling. (Fixes Github #1953).
* render/bgfx/blendreader.cpp: Support non-separated blend mode specification for BGFX effects.
* render/bgfx: Reworked how horizontally-padded screen textures are handled. Likely fixes MT08512 and MT08505.
* render/bgfx: Ensure that a texture's width margin is updated in all cases.
* render/d3d/d3dhlsl.cpp: Fixed tinting in HLSL post-processing mode.
* render/d3d/d3dhlsl.cpp: Avoid most redundant state-setting calls. Reduces D3D API calls by about 90% on fruit machine drivers.
* render/d3d/d3dhlsl.cpp: Assign SourceDims and QuadDims uniforms to only those effects that use them.
* machine/laserdsc.cpp: Always add video quad to screen container, adjust tint based on m_videoenable instead.
* crt-geom-deluxe: Increased number of taps for halation and increased maximum width.
* crt-geom*: Moved repeated crt-geom/crt-geom-deluxe functions into their own file.
* crt-geom and crt-geom-deluxe: added support for sRGB output gamma ramp and made it the default.
Made pbobble parent of bublbust, as it seems to be more widespread and
more complete. Also fixed some ROM labels for bublbust.
Made tbyahhoo parent of mtwinbee as the latter has substantial content
removed rather than being localised, making it less complete.
Applied srcclean to JSON files in bgfx subtree.
* Made spot size parameters adjustable also increased samples from 2 to 3 scanlines for crt-geom-deluxe.
* Made horizontal interpolation adjustable.
* bgfx crt-geom-deluxe: Made phosphor decay smoothly to zero at specified cutoff time.
* bgfx crt-geom-deluxe: Added lowpass filter.
Added a "brightness boost" feature for the shadow mask that works by making the brightness ratio between bright and dark mask pixels closer to 1 for the brighter parts of the image.
Added clamping to zero so that underscanning produces a black border.
Added a "raster bloom" effect to crt-geom-deluxe that makes the image grow slightly when the average brightness of the screen is high, mimicking a common defect in CRTs.
This includes several aperture grille / shadow mask patterns. Note that these are all designed to be used on a display with RGB subpixel order, and may thus suffer if rotated or used with a BGR display.
