Make straighten/orthogonalize act like a single operation

- Display only one or the other in the radial menu
- Rename "Orthogonalize" to "Square"
- Use "S" as shortcut for both

Refs #1839
Added the ability to load points from gpx files and display on the map
Clean up
Update togeojson.js to 0.3.0
Don't auto-save intro tutorial edits

Fixes #1745
Fixes #1795
Update imagery
Update translations
1.2.0
Start FAQ
Can I use iD offline?
Add office to area list (fixes #1784)
Add more tags to areas list

Keys added from osm2pgsql, excluded values from overpass turbo
Merge pull request #1849 from pnorman/patch-2

Add more tags to areas list