Request: `SuperEllipse` and `SuperEllipticalArc` shapes

[feature request] Make Cap and Join enums repr(u8)

Fillet (round corners) operation

stroke() function with dashed stroke returns first piece last

New stroker can produce NaN paths

Use `core::error:Error`

Use builder pattern for BezPath

Consider using a trait for `callback` in the `flatten` method insead of a callback

[sparse_strips]: Incorrect dash rendering

Add `point_on_shape`