Bug/known issue: The Apply Changes window doesn't display the list properly at the bottom if there are a lot of packages in the list.

[DrewNaylor]

This is the same issue as in #117. I tried to do the PerformLayout thing on it, but that didn't end up helping. Version 0.3 and likely older versions are affected, in addition to 0.4 possibly being affected unless I figure this out by the time it's ready.

Workaround: Maximize then unmaximize the Apply Changes window with the package list scrolled to the bottom. This should let you access the bottom items properly. Closing then re-opening the Apply Changes window with the same packages marked may also make it work.