* Update GLTF support to include loading color for albdeo (saved in the color value of the materialmap), support occlussion and emmission maps.. as well as some quality of life updates.

* clean up to use single image

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

Added SUPPORT_TRACELOG_DEBUG config

Renamed for consistency with Vecto2Scale()
Also renamed Vector3MultiplyV() to Vector3Multiply()

* Normal vbo not correctly updated

Uses fewer vertexes than using DrawCube() or DrawSphere() for points.  The small line is on analogy to the code for DrawPoint() in shapes.c.

* explained a bit more the core_window_letterbox example

* fixed a few 'ups' moments that could lead to mild head pain and time loss

* Initial commit of addition for GLTF materials.. should support loading more than just albedo map.

* Clean up

* fixed seg faults and leaks

* temp don't overwrite defuse colour when rendering

* undid something dumb!

* correctly mixed diffuse map color when rendering to preserve not overwrite it

All data should be properly initialized by now

- Mesh, Shader, Material structs have been reviewed to minimize size when passed by value, all required code has been reviewed.
 - GetCollisionRayModel() reviewed to avoid pointer, not required because model is not modified inside the function
 - UnloadMesh() reviewed, pointer not required
 - CheckCollisionRay*() parameters name reviewed

Free texturePath in LoadGLTF()

* Fix loading multiple animations from .iqm file

* Fix memory leak in models_animation example

* Added export instructions to the animation example

* use raylib free

* include <stdlib.h> to appease the travis CI gods

* replace tabs with spaces

* Update year of copyright notices

* Fix mistake in comment

* Fix typo ("algorythms")

* Replace tabs with spaces

* Remove trailing whitespace and fix mistake in comment

* Fix ExportImageAsCode missing comment rectangle corner

* Replace tab with spaces

* Replace tabs with spaces