make toolbutton optional Rated 4 out of 5 stars

I've noticed in FF4b12 I'm able to deinstall this AddOn.
I like the concept, and would like to participate in future studies, but without a button in the toolbar.
Please change this AddOn to just sit in the background, but leave the toolbar alone. Don't force the button, even after I've removed it manually (move the notifications somewhere else).

This review is for a previous version of the add-on (1.0.3.1-signed).