Experiment: bazo crate for vocabulary types (Point, Size, Rect, etc)

[nicoburns]

An experiement in making a base vocabulary crate to sit under kurbo (could also be used in parley, peniko, taffy, etc. This crate is similar to euclid, except that it doesn't have a type parameter for the units making it much more ergonomic to use.

The idea is that this crate would be highly stable (rarely if ever making breaking changes).

Tasks

• Duplicate kurbo crate as bazo
• Remove kurbo-specific code from bazo
• Make bazo types generic (rather than hardcoded to f64)
• Use bazo types in kurbo and ensure all impls still work

Open questions

• Is this a good idea?
• Should Stroke, Cap, Dash, etc be included (in limited form)?
• Should BezPath, CubicBez, QuadBez (in limited form)?
• Where should the kurbo SVG path parsing code live (separate crate?)
• Should this depend on num-traits or have it's own number abstractions?