`physac` is available on its own repo

This reverts commit d786af83fc.

* Comparison is always true because finalSample >= 1

* Comparison is always false because keyCount >= 0

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

* Add support for truncating parser input

* Remove RLAPI from implementations in rlgl.h

This immediately shows log messages when stdout is not connected to a
tty.

Remove line that caused a memory leak

Avoid calling `abort()`, `LOG_ERROR` already manages it. Code looks cleaner now.

* Augment raymath.h with useful functions

* Rename Vector2ClampMagnitude and Vector3ClampMagnitude to Vector2ClampValue and Vector3ClampValue

* Remove Vector3{Up,Down,Left,Right,Forward,Backward}