ADDED: rlGetPixelFormatName()

When a shader is loaded, by default, several locations are tried to be set automatically.

Reviewed locations descriptions

Replaced: Returns -> Get

Now rlgl only depends on OpenGL and it's completely decoupled from platform layer libraries (EGL)

It works compiling with MinGW

Added config flag: SUPPORT_GL_DETAILS_INFO

Operate over global variable

Removed functions from rlgl module.

Avoid RLGL data dependency to allow moving the functions somewhere else

As a bonus, stereo render is compatible with mesh instancing now!

rlgl module has been completely redesigned to move Mesh/Material structures to [models] module. Still some work to do, broken elements:
 - [models] OpenGL 1.1 mesh rendering: DrawMesh()
 - [models] Mesh Instancing: DrawMeshInstanced()
 - [models] Stereo rendering: DrawMesh()
 - [models] GL_FLOAT, GL_UNSIGNED_INT exposed
 - [models] GenMeshCustom()
 - [rlgl] GenTexture*() functions removal?

- Many functions renamed to follow rl*() convention
- Some internal functions exposed in the API
- Some functionality moved to other modules
- Reorganized all functions by categories
- Make sure it keeps working with OpenGL 1.1 and 2.1

- Some rlgl functions have been moved to core
 - Some functions have been made internal to rlgl
 - rlgl functions prefixed with rl*()

Vr simulator has been moved to core module and completely redesigned. Now user is in charge of stereo-render fbo and also in full control of distortion shader. Code is a bit more complex but better aligned with other raylib examples.

Now enum names are more consistent between them.

Just assigned a fixed memory size for custom Material parameters in case of being required, so we shouldn't worry about allocating/freeing them.

Checking for extension and enabling it if available