Another round of usability fixes

Another round of small improvements:

- Cycle through colors instead of randomly choosing them.
- If a service window is invalid, or has fields deleted, it fades back and is not included in the calculation. This lets a planner do things like turn off weekend service
- Add a 'New Map' button on the bottom right. Will need some more design love in the future.
- Fix IE scroll overflow issue
- Fix share link in IE (window.location.origin is not supported)