Clean up source code.

Fixed:
- mixed tabs/spacing
- trailing whitespace
- unneeded semicolons
Remove state connectors that do not join sequential ZIP's.
Use broader range of state colors.
Change hard tabs to soft tabs.
Add option to display connector direction.
Syncronize JS settings to state of checkboxes on init.

Firefox remembers the state of the checkboxes between page loads.
Use Dojo FilteringSelect widget.