Fix widget install and uninstall

This is a suggestion to fix issue #2206 (and #2133).

I don't know if it's the best way to solve the problem, but I wanted to suggest it.

No symlinks are created, so OSX won't report that there's a newer version of the widget. The only drawback I see with this fix is that every time you install a widget, a popup asking for confirmation will appear.

What do you think?

Fixes #2206
Fixes #2133