Draft: Add hatch to path functionality.

This is ready for preliminary testing. For the moment, the path created from the hatch is shown in purple and the hatch is not removed. This is to allow comparison between the original hatch and the new path. There also needs to be a discussion on what the UX for this feature (should hatches automatically be converted to paths when "Object to Path" is invoked? should there be a way to convert hatches to paths outside of this menu item?, etc.).

A number of rendering bugs are also fixed, mostly for when 'hatchUnits' or 'hatchConentUnits' are objectBoundingBox and when the hatch 'x' and 'y' attributes are not zero.

There is a rendering bug that depends on zoom, introduced sometime after 1.2.x. This effects mostly paths that overflow the nominal strip region.