Corrected issue with sound playing (pop sound at the end)

Still a work in progress but it already works...
Current riqm API could be simplified...

This change allows rlgl.h usage as independent single-file header-only module... still some tweaks required, like removing GLAD dependency... required extensions could be manually loaded!

Also removed shader_distortion.h, embedded in rlgl.h

Note for me: Replace All is NOT your friend...

Added: data to CharInfo struct
Added: LoadFontData()
Added: GenImageFontAtlas()
Removed: LoadFontEx()
Removed: LoadTTF() [internal]
Some code tweaks

Reviewed: GetImageData()
Reviewed: ImageFormat()

- Preparing MP3 files support
- Jumped version to raylib 2.0-dev (too many breaking changes...)

Note that only some lib versions have been updated

Not required any more!