Implement a line and marker style config tool for matplotlib plots

Initial implementation of a line and marker style and color
confguration tool. The implementation uses sample class matching to
determine the correct styles to apply, allowing cumulative class
styles by subset attributes. Multiple search methods are implemented
including exact, in, begins, ends, and regexp (not yet implemented),
and all standard matplotlib style features can be configured.

Automated matching is performed for classes that do not hit any
pre-defined rules, and auto-rules are generated (exact match).

An 'Appearance' toolbar is added, with the config available within.