Changes:

 - Font structure has been redesigned, CharInfo structure contained character rectangle within font texture, it has not much sense, considering that it was an information relative to the font atlas generated and not the character itself, so character rectangles have been moved out from CharInfo to Font.
 - CharInfo included a data parameters to contain character pixel data (usually grayscale), generated on TTF font generation. It was inconsistent with other fonts types, so, now CharInfo includes directly an Image of the glyph.
 - REDESIGNED: GenImageFontAtlas(), additional recs parameter added, loaded and filled inside the function to export atlas characters rectangles, instead of silently modify the input CharInfo data.
 - REVIEWED: ImageTextEx(), funtion retrieved the font atlas image from the GPU, that was slow and problematic in several platforms. Now it uses directly the CharInfo image. Support for unicode codepoints has also been added.
 - REDESIGNED: ImageDraw(), now it includes an additional parameter, the color tint, not only it could be useful for several situations but also function signature is more consistent with similar functions.
 - ADDED: ImageFromImage() to generate a new image from a piece of another image.
 - REVIEWED: GetNextCodepoint(), renamed parameters to be more clear.

Also all examples and games that were affected by those changes have been reviewed.

Added a bunch of useful text management functions.
Consequently, some already available functions like `FormatText()` and `SubText()` has been renamed for consistency. Created temporal fallbacks for old names.
raylib version bumped to 2.3.

Changed parameters order for consistency with LoadFontData() and other functions when an array is passed by parameter and array size is the following parameter.

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

Game developed in the GGJ18, it has some bugs and ending screen is
incomplete... I'll try to keep working a bit more on it.