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

Also added new compilation FLAGS for that pourpose

Allow compiling the library with support for automatic screen capture
(KEY_F12)

Added raylib version to config

I would have liked config.h to be selected by include dir configuration,
but this way is less intrusive.

That way, a user needs only to touch a single file to configure what
features raylib is built with.
Include guards are left out intentionally, because config.h should only
be included in source files, not headers.

Later on, config.h can also define the raylib version (#461).