Probably useless but interesting for education. It generated a grayscale image directly from text data.

- 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()`.

* Update raylib.h

* CheckCollisionPointPolygon()

* typo

* Fix Undefined Symbol `_ftelli64`

* Add files via upload

* Update raylib.h

* Update raylib.h

Those functions were platform dependent and user has no control over the file created. They have been removed from raylib and just moved to `core_storage_values` example.

(GetMouseWheelMoveV).

REDESIGNED: `LoadDirectoryFiles()`
ADDED: `LoadDirectoryFilesEx()`
REDESIGNED: `LoadDroppedFiles()`
ADDED: `IsPathFile()`

This BIG BREAKING change simplifies the functions and gives more control to the user:
 - A new `struct FilePathList` has been added to avoid exposing complex pointers.
 - User is responsible of memory loading/unloading
 - Filepaths loading support recursive directories and file extension filters

* GetMonitorWidth()/GetMonitorHeight(): current video resolution instead max available

* adapt header comment to reflect change

RENAMED: `ClearDroppedFiles()` to `UnloadDroppedFiles()`

RENAMED: `ClearDirectoryFiles()` to `UnloadDirectoryFiles()`

Events waiting can be enabled/disabled, it toggles event polling.

When referring to byte array SIZE, I find it more clear than length

This feature is still under consideration/testing and it doesn't work properly, at least the Delay Effect processor.

WARNING: This addition is based on a PR and it's still under review, not sure if it will be maintained in the future. In general, raylib tries to avoid callbacks usage mechanisms.

* make const

* make const

* follow style guide

* Update rmodels.c