Redesigns, deletes and renames

Also noted authors propertly on contributed examples

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

Now it uses CharInfo data, this way, it's better aligned with the future
RRES file format data layout for sprite font characters.

Examples have been renamed for coherence with raylib modules and test
examples have been merged into examples folder.

Check CHANGELOG for the list of changes in this release!

View CHANGELOG for details