Add a simulated command-click path menu

[Uncommon]

Since the title bar is all a custom toolbar, command-clicking on what appears to be the window title doesn't do anything.

The title should respond to command clicks:

• [ ] Display a popup menu showing the list of parent folders
• [ ] Include appropriate folder icons
• [ ] When a folder is selected from the menu, open it in the Finder

[Uncommon]

This gets difficult because, among other things, there doesn't seems to be an easy way to have a view that can drag the window on left click but not right click.

[Uncommon]

Outdated: Toolbar uses standard controls now.