[REVIEW ONLY] Dark UI theme for inline editors

This is a spinoff of @larz0's work in #8362 with a goal of fixing #8379.

As of this initial push, I have done inline CSS and color editors. The timing editor is almost done, and quick docs remains.

cc @MiguelCastillo
Example:

![themes-dark-dialog-title](https://cloud.githubusercontent.com/assets/1197144/3696075/5d209f98-1388-11e4-8038-99dc40d65cad.png)