- ADDED: `GetCodepointPrevious()`
 - RENAMED: `GetCodepoint()` -> `GetCodepointNext()`, actually, reimplemented
 - `GetCodepoint()` has been kept for the moment, for compatibility and also because implementation is different
 - RENAMED: `TextCodepointsToUTF8()` to `LoadUTF8()`, simpler name and more aligned with raylib conventions (functions loading memory start with Load*()), parameters should be descriptive of functionailty.
 - ADDED: `UnloadUTF8()`, aligned with `LoadUTF8()` to avoid allocators issues.

This adds `ImageDrawCircleLines()` and `ImageDrawCircleLinesV()` to draw outlines of circles, and updates `ImageDrawCircle()` draw a filled circle to match the effect of `DrawCircle()` and `DrawCircleLines()`.

Updated version to `rlgl 4.2`

Dimensions of Rectangle should be casted to int before multiplication,
otherwise there is a risk for underallocation/overallocation of memory.

Height of the rectangle can be float, which
may lead to doing extra iteration of loop and
writing out of bounds.

This is a tiny change that makes code in src/rtextures.c "fold"
correctly in editors/IDE's by matching the number of opening
parenthesis to closing parenthesis.  One of those editors is Emacs ;-)

Added a note for a future improvement

Allow to choose which modules are compiled with raylib, if some modules are excluded from compilation, required functionality is not available but smaller builds are possible.

Allow texture loading with no data transfer (in case image.data = NULL)

raylib was using `stb_perlin.h` library to generate perlin noise, it seems that recently this library has been flagged as it could be infringing some algorythm patent. For security, it has been removed from raylib.

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.