* Added optional GPU skinning

* Added skinned bone matrices support for different file formats.

* Moved new shader locations to end of enum to avoid breaking existing examples. Added gpu skinning on drawing of instanced meshes.

* Added GPU skinning example.

* Removed variable declaration to avoid shadowing warning.

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

Updates skybox demo to show how to do both HDR and non HDR skyboxes

Co-authored-by: Jeffery Myers <JefMyers@blizzard.com>

* Fix bug #1270

Added an argument to the shader in order to flip the texture

* Fix Bug #1270

* Fix bug #1270

When using FormatText() several times in same function, returned string is static and so, the same is returned, resulting in failures on shader loading.