Show directions polyline on map.

Adds button to go to map in directions view; if map view opened from there;
map will show directions overview polyline and zoom to fit its bounds.
Add new icon for contact address picker
Show custom icons for user address and current location.

Current location icon only shown if viewing directions polyline from that point.
Merge pull request #39 from flibbertigibbet/feature/show-directions-line

Feature/show directions line