Svgelements

.length() / .point() for lengthless paths no longer crashes.

This version mostly corrects use/defs tags. These now are parsed inline with the data set.

Arcs have changed `arc` and `sweep` to `arc_flag` and `sweep_flag` to make them distinct from sweep.

Arcs allow definition based on a control point or a bulge.

Fixed several minor bugs.

Corrects inverse matrix
Adds invert dunder '~'.
Adds coverage for inverse matrix.

Few required softened edges

Improvements to .bbox() so that they are standardized for most SVGElements.

Elements contain a dict of values, this permits parsed SVGElement classes to provide non-parsed values to agents utilizing the objects.

-- Also, corrected a small bug with SVGImage viewports.