Added window drop files support

Now gestures system can be used as standalone module

Camera system can be used as standalone module

Now audio module can be used as standalone module

Shader functionality owns to rlgl, not core module

Added:
- LoadImageRaw()
- ImageCopy()
Renamed:
- GetPixelData() -> GetImageData()

Now it supports multiple maps one next to the other

Corrected issues with textures loading

Corrected shader version depending on OGL version
Corrected bug in gestures module

Complete review of matrix rotation math
Check compressed textures support
WIP: LoadImageFromData()

- Camera system moved to a separate module [camera.c]
- WIP: Added customization functions for camera controls
- Added custom shaders support on batch drawing
- Complete redesign of textures module to support multiple texture
formats (compressed and uncompressed)

Moved functions: LoadShader(), UnloadShader()
Add support for PVR textures compressed/uncompressed
WIP: Detect available extensions for compressed textures

Support multiple texture formats (uncompressed and compressed)
Postprocessing shaders support
Model struct redefined and improved
Extended loading functions for Textures and Models
Simplified functions: DrawPlane(), DrawQuad()
Deleted functions: DrawPlaneEx(), DrawGizmoEx()
Now Text module only depends on Textures module
Shapes: Reviewed functions to low lines/triangles usage
Removed useless tabs and spaces around code

Extended default raylib font system to support Latin-1 Supplement
characters

Corrected GetMouseWheelMove()
Corrected camera system
Reviewed cubicmap resolution (collision detection)
Added QuaternionTransform()
WIP: Raycast system (not working)
WIP: Reviewing axis-angle rotations...

Shader system has been completely redesigned
Added support for multiple texture color modes