Serving mode

This work includes:

- pushing to the vendor map after login
- allowing the vendor to set their location by dragging and zooming the map
- allowing the vendor to go into "Serving Mode"
- super sweet animation to assure the vendor they are in Serving Mode :)
Don't add the `.png` ending. That way the OS will pick up on the ending automatically and will automatically choose the correct icon (regular vs @2x) based on the device. Hardcoding .png makes it ignore @2x every time.