Feature: Path Shape & Tool

[laszlokorte]

Currently we can only create Rectangles, Circles, Pies, Arcs, Lines and Text shapes.
Each of those shapes has a fixed number of values determining it's position and orientation.

Circle: Center, Radius
Line: Start, End
Pie: Center, Radius, Angle1, Angle2
Arc: Start, End, CenterOffset

Those values are allocated on the runtime stack.

A Path shape has a variable number of points. The runtime must support some kind of heap allocation to allow allocating memory for the points of a path at runtime.