Trim Down Toolbar Customization Options

Toolbar customization is a little out of hand. There are so many silly options there that we're hiding cool features. Here's my quick overview:

* If you had the tab trash can in the tabbar like dynamic notebook, you would no longer need that option.
* I don't see the point to a "Close tab" tool item since that is already on the tab
* I don't think we need a "Find..." tool item. Nobody has this. It's also already available from the menu
* Fullscreen is available from the menu
* New window is available from the menu
* Next and forward is kind of complicated. I'll skip that for now
* Not sure of the use case for "open" but I'll also skip that
* Preferences is available from the menu
* Print is available from the menu
* Save page as... is available from the context menu
* Side panel is available from the menu
* Tab list button should probably be an extension that also disables the tab bar like the tab panel extension
* Web search is available from the url bar. You already know I think we should remove this redundant UI
* Zoom in and Out are available from the context menu (edited)

So that leaves only Bookmarks, Homepage, and Next/Forward as valid tool item options. We could argue that the "one true" bookmarks UI is the sidebar and drop that option.