menu applet: Fix applicatoin list not scrolling with selection when using
keyboard navigation (regression from autoscrolling implementation)
menu applet: sometimes the vector box calculation ends up with a negative width
causing a harmless wm warning, and making the box stick around longer than it should.
This removes it in that case, as 100% of the time we're over the app list now and
don't want it.
Merge pull request #1958 from mtwebster/menu-offscreen

Fix a couple menu regressions from scrolling and polygons