Mega Bezel shaders

[Jackster3000]

So thanks for adding in the Mega Bezel shaders first off. It really adds to your wonderful program. I have some things I'd like to add about them:

1. If possible, can you also add in the shaders from this folder:
   https://github.com/libretro/slang-shaders/tree/master/bezel/Mega_Bezel/Presets/Base_CRT_Presets

While I appreciate the regular Mega Bezel shaders, these ones add in additional parameters not present in them such as NTSC, LCD, and Megatron settings.

2. The parameter dialog has some words that are cut off, which makes it hard to see when it explains the settings the slider needs to be in.

[mausimus]

Thanks, yes will do both.

[mausimus]

Added in 0.94; the Megatron presets failed to compile because some passes rely on HDR texture formats which SG doesn't yet support (I don't have an HDR display) but hopefully this helps. Also extended UI space for parameters (you can also hover for a tooltip).