v0.2.0 (milestone 2)

The main (only?) change in this release is a very large refactoring of the theme, and its API. This is prep work for the future milestones, that will bring a Swing LaF bridge theme to use in the IDE.

While we don't expect things to change further in a dramatical fashion, please keep in mind they well may need to, if we discover some new issue or limitation we need to address.

Note: since this is a large refactoring that changes significantly the code and its architecture, expect a painful migration if you were customising things a lot. We also have a number of known visual glitches/regressions since the first milestone, which we'll address over the next few releases.