raylib modules have been slightly renamed to add some identity and note that they are independent modules that can be used as standalone separate parts of raylib if required.

The renamed modules are:
 - `core` -> `rcore`
 - `shapes` -> `rshapes`
 - `textures` -> `rtextures`
 - `text` -> `rtext`
 - `models` -> `rmodels`
 - `camera` -> `rcamera`
 - `gestures` -> `rgestures`
 - `core` -> `rcore`

All the build systems has been adapted to this change.

Following english rules, it should be singular name before Count.

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