Add 'Help→About' dialog box and menu item.
Implement pin pass-through rendering, to show when maps are and aren't modified.
Implement pin type negotiation (e.g. variants and hvars)
Implement graph zooming.
Add option to restore default filter name after using rename.
Measure filter width to account for long filter names.
Add tooltips for toolbar buttons.
Add 'move filter' menu option.
Allow multiple selection (for move/delete/disconnect options?)
Add hotkeys:
'o' for filter options.
'r' for rename.
'del' for delete.
'd' for disconnect.