[Input] Added Mouse.GetCursorPos() (WIP)
[Input] Improve SDL2 and Windows GetCursorState
[SDL] Use h-wheel events
[Examples] Test Mouse.SetPosition
[Mac] Implemented Mouse.GetCursorState()
[Examples] Improved Mouse.GetState output
[X11] Improved XI2Mouse implementation

Horizontal and vertical smooth scrolling is now supported.
Movement axes are now correctly identified. Device hotplugging
has been improved.
[X11] Fixed XI2Mouse smooth scrolling

The scrolling valuator offsets are now calculated correctly, based on
the number of set bits in the valuator mask.
Additionally XI2Mouse now runs on a background thread, using blocking
XIfEvent. This should improve resonsiveness and reduce CPU usage, due
to reduced polling.
[X11] Flush XSendEvent on exit