fix getWidth() and getHeight()

These now represent the current width and height of the Zone, instead of
the original
add PieMenuZone

This is a Pie/Radial Menu implementation
(https://en.wikipedia.org/wiki/Pie_menu), Based on Pie Menu
Implementation by amnon.owed :
https://forum.processing.org/topic/pie-menu-in-processing#25080000002077693