Reason for removal: This function forces a specific Image data format, it copies data internally (it could be confusing and lead to memory leaks), it's redundant, there is a simpler alternative and raylib promotes using structures directly

Some internal defines have been exposed in config.h

* Implemented DrawTextureTiled()

* Example added

Probably there is a better way to do this but this is a temporary solution for backward compatibility

After multiple tests and lot of redesign, current implementation is the fastest one. It also considers several fast-paths for maximum speed!

WARNING: Some functions ADDED and some RENAMED:
- RENAMED: Fade() -> ColorAlpha() [Added #define for compatibility]
- ADDED: ColorAlphaBlend()
- ADDED: GetPixelColor()
- ADDED: SetPixelColor()

Trying a new optimization approach, some additional functions added, they will be probably exposed soon.

Despite all the effort put on function optimization, dealing with alpha blending is complex, considering src and dst could have different pixel format...

Optimized to avoid ImageCrop() calls, now we define the source image rectangle and we just copy that data over the new canvas.

Always using RGBA for now.

Further optimization, moving data line-by-line
Old optimization left for reference

Using ImageResizeCanvas()

Now uses GetImageAlphaBorder()

Avoid GetImageData() retrieval and free

Added several optimized options for future reference (if required)

Compression API requires functions provided by stbi_image_write (DEFLATE compression)

Several functions used to load external files have been reviewed to just load the full file with LoadFileData() and load data from memory from there. This way all file access functionality is centralized in utils module.

Functions reviewed: LoadDDS(), LoadPKM(), LoadKTX(), LoadPVR(), LoadASTC(), SaveKTX()

At this point LoadImageEx() could be removed from raylib... still thinking about it...

ImageDraw() is actually used in multiple functions and it aslo depends on several functions...

Removed ImageAlphaMask() dependency on [text] LoadBMFont()