* Extend the PaneSwitch BControl from Tracker, so it can draw on/off labels.
This has the added benefit that you can click the label to expand/collapse,
like for example in the Get Info window (Permissions).
* I also added font-sensitivity features to PaneSwitch, and it can be used
in layouted windows (untested).
* This made the "DrawButton" in the Installer superfluous.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30348 a95241bf-73f2-0310-859d-f6bbb57e9c96
