Avoid out-of-bounds situation with button array

- Support up to 4 gamepads
- Unified system between platforms
- Corrected some bugs

Corrects weird artifacts on web

A simple 1st person camera... still requires some work...

Useful if text module is not required...

Function was inefficient and should be rewritten from scratch, it
probably neither belongs to this module but an example...

Sincerely, don't like it... it should be ported to quaternions... the
way it manages cameraTargetDistange and cameraAngle is confusing...

When SetTargetFPS(0) app crashes horribly (division by zero)

Removed internal Camera, not required any more
Removed useless functions

Removed support for some unusual image formats

Weird, OVR_Version.h still points to 1.7, probably a typo...

raylib uses spaces between '+' and '-' signs but not between '*' and '/'
signs, it's a chosen convention

- LoadWave()
- LoadWaveEx()
- UnloadWave()
- WaveFormat()
- WaveCopy()
- WaveCrop()
- GetWaveData()

Greater LoadOBJ() flexibility

LoadOBJ can now load objects with having no texture coordinates or
objects having texture coordinates specified as tuples.

Fix a typo in the DrawCube, DrawCubeWires and DrawCubeTexture definitions