Documented that event channels can be assigned to each other to collapse events.
Removed unnecessary space if the secondaryText argument to MsgBox***() is an empty string. This doesn't change much on Mac OS X; it always shows the informational text field, showing an empty string by default. On GTK+ it seems to get rid of the bold over the primary text; I'm going to assume this is intentional (it looks that way on GTK+ 2; the HIG docs have outdated screenshots...).
"Fixed" the zero-size Combobox drop-down on Windows by having Windows fix it for us (and since we did everything we need to do to get it to fix it for us, it was already fixed!).
More TODOs.