Bug 1031094 - Uninstalling a collection web result unpins it from collections. r=kgrandon

Sorry for not being clear, I think we still need to keep this, but can probably just avoid sending the event to the collection app.

We want to keep the removeIconFromGrid() call to keep the state in sync with other homescreens. I believe the path for this is when a user changes to another homescreen, deletes a bookmark, and changes back. This line should remove it from the vertical homescreen.