rlgl has been redesigned to avoid any dependency to `raylib` or `raymath`, all functions using some of those libs have been reviewed.
 - REMOVED: `Texture2D`, `Shader` structs dependency
 - REMOVED: `Vector3`, `Matrix` structs dependency
 - REMOVED: raymath functions dependency, all required math is implemented in rlgl
 - ADDED: `rlMatrix` custom rlgl type
 - ADDED: `utils.c`: `rlMatrixFromMatrix()` and `rlMatrixToMatrix()` for a safe conversion between raylib<->rlgl matrix types
 - ADDED: `rl` prefix to all `rlgl` structs
 - Other small tweaks here and there

Co-authored-by: Lambert Wang <lambert.ww@gmail.com>

Co-authored-by: Simon <simon@frithrah.com>

Use fabsf() instead of abs()

* CheckCollisionPointTriangle

* New feature proposal to existing collision detection routines.
It checks if point [point] belongs to line created between two points [p1] and [p2] with defined margin in pixels[threshold].
1693

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?

Function analyzed using RenderDoc. It's a complex function and could require many triangles for the corners but it seems overall it's quite optimized!

- The vertices did not map to where I expected causing rotation to be
off by 90 degrees. I reorganized the vertices making it easier to
reason about which fixes this.
- The order for drawing is now topLeft, bottomLeft, bottomRight,
topRight.

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

* Optimize DrawTexturePro and DrawRectanglePro transformations
- Add check so rotation is only applied if rotation != 0.0f.
- Replace matrix usage by calculating the vertex data directly.

* Fix error with windows build and trim whitespace

Co-authored-by: Simon <simon@frithrah.com>

* Fixed DrawLineEx

Corrected the issue https://github.com/raysan5/raylib/issues/1596

* Removed raymath dependency for DrawLineEx

* Add quadratic bezier to shapes.c

* Add DrawLineBezierQuad to header

Removed function from raymath

Pefixing/Suffixing some data type identifier in the variables is not a convention used in raylib, just reviewed it for consistency...

Still, I kept the *Rec suffix in some functions.

Most warning were related to types conversion (casting required) and unsigned/signed types comparisons.

Added preprocessor directives (_CRT_SECURE_NO_DEPRECATE; _CRT_NONSTDC_NO_DEPRECATE) to avoid warnings about unsafe functions, those functions are safe while used properly and recommended alternatives are MS only.

Some external libraries still generate warnings.

There are multiple #define values around raylib, usually not exposed for redefinition, just reviewed all of them to allow users redefining them on compile time if required.

Also, multiple #define have been renamed and commented.

Just for clarification, no plans to remove libc dependency, just did some code analysis to see how much raylib depend on stardard C library. My conclusions:

 - stdlib.h: primary dependency is for malloc() and free()
 - stdio.h: primary dependency is for FILE access, maybe it could go through a custom ABI?
 - string.h: just around 8 functions required
 - math.h: just around 8 functions required
 - others: 1-2 functions required for some other headers

* [core] REDESIGNED: Implement global context

* [rlgl] REDESIGNED: Implement global context

* Reviewed globals for Android

* Review Android globals usage

* Update Android globals

* Bump raylib version to 3.0 !!!

* [raudio] REDESIGNED: Implement global context

* [raudio] Reorder functions

* [core] Tweaks on descriptions

* Issues with SUPPORT_MOUSE_GESTURES

* [camera] Use global context

* REDESIGN: Move shapes drawing texture/rec to RLGL context

* Review some issues on standalone mode

* Update to use global context

* [GAME] Upload RE-PAIR game from GGJ2020 -WIP-

* Update game: RE-PAIR

* [utils] TRACELOG macros proposal

* Update config.h