* Fix tcc not finding emmintrin.h

This allows to compile raylib with tcc with no errors.

* Remove __TINYC__ check from stb_image.h

This will be placed under textures.c

* Move tcc check to textures.c

Avoiding to change stb_image.h

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

* Implemented remaining 7/8 of ImageDrawLine

The existing code was correct for one octant, it now works for all 8
Added two internal functions, _ImageDrawLineHorizontal and _ImageDrawLineVertical, whithout which it would've been 4 times as much code.

* ImageDrawLine: Replaced 3 functions with 1

Removed both freshly added internal functions
Crammed it all into one

* ImageDrawLine shortened significantly using maths

Substituted X and Y, then wrote one abstract loop instead of 4 specific loops.
Lots of comments to explain what I'm doing for future maintainers.

* Now conforms with style conventions

Also reworded a comment to sound more... fomal.

RENAMED: GetTextureData() -> LoadImageFromTexture()
RENAMED: GetScreenData() -> LoadImageFromScreen()

ADDED: rlGetPixelFormatName()

RENAMED: GetCodepoints() -> LoadCodepoints(), now codepoint array data is loaded dynamically instead of reusing a limited static buffer.
ADDED: UnloadCodepoints() to safely free loaded codepoints
RENAMED: GetNextCodepoint() -> GetCodepoint()

Replaced: Returns -> Get

- Dividing by height instead of width results in missing parts of the image.

Removed functions from rlgl module.

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?

* adds DrawTexturedPoly with example

* the actual example ... ahem

* moved DrawTexturePoly to textures function and example
NB function name changed to fit with other DrawTextureXXX functions
(no "d" )

Co-authored-by: codifies <you@example.com>

- 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.

- 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

* 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

Now enum names are more consistent between them.

Some enums values have been renamed to be more consistent and also provide a more detailed description:
 - ShaderLocationIndex:    LOC_VERTEX_POSITION -> SHADER_SHADER_LOC_VERTEX_POSITION
 - ShaderUniformDataType:  UNIFORM_VEC2 -> SHADER_UNIFORM_VEC2
 - MaterialMapType: MAP_ALBEDO -> MATERIAL_MAP_ALBEDO
 - PixelFormat: UNCOMPRESSED_GRAYSCALE -> PIXELFORMAT_UNCOMPRESSED_GRAYSCALE

This new flag allows omitting stdio.h library in case of a custom implementation is used.

RENAMED: TextureFilterMode values
RENAMED: TextureWrapMode values

RENAMED: CubemapLayoutType and NPatchType

* Don't use DrawRect to clear an image, a pixel loop is an order of magnitude faster.

* Update ImageDrawRectangle to be faster too.

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.

This is a BREAKING CHANGE!

To address the linked issue, several functions have been renamed and couterpart functions have been created to free loaded memory:
 - RENAMED: GetImageData() -> LoadImageColors()
 - RENAMED: GetImagePalette() -> LoadImagePalette()
 - RENAMED: GetWaveData() -> LoadWaveSamples()
 - ADDED: UnloadImageColors()
 - ADDED: UnloadImagePalette()
 - ADDED: UnloadWaveSamples()

Since I don't think the purpose of raylib is to save space compressing image, I think it could be a good idea to keep quality from 90 to 100.

Let the advance users manage it as they want...