Make iD default editor

Make iD the default editor for all users that have not specified
a preferred editor, except fall back to P2 on IE.
Add nominatim translation for historic=tomb
Update Potlatch 2 to 2.3-603-gebdfa12 build
Update Potlatch 2 to 2.3-605-gbec0ea7 build
Fix test to make sure it picks up the right token
Remove Donate Ad Banner
Compact user menu
Convert edit menus to bootstrap dropdown
Specify width and height for image

User-uploaded images don't get automatically scaled
like Gravatar images do.
Use user_thumbnail_tiny
Pare menu down to basics
Drop role and aria attributes
Consistent title case
Merge remote-tracking branch 'osmlab/user-display'
Merge remote-tracking branch 'osmlab/id-default'
Update to iD v1.1.5
Build an asset manifest for iD
Remove unnecessary z-index for sidebar headings
Rework piwik configuration
Add support triggering a piwik goal when a map layer is selected