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
Orthononalize bug fixes
Merge pull request #1852 from paulmach/ortho-bugs

Orthononalize bug fixes
Improve Circularize Action
more clever splitting of closed ways

if a way is closed, iD needs to choose a second node to
split the way at.

This algorithm looks for a node that is both far away from
the initial node in terms of way segment length and nearby
in terms of beeline-distance. This assures that areas get
split on the most "natural" points (independent of the number
of nodes).

For example: bone-shaped areas get split across their waist-
line, circles across the diameter.
Add iD.geo.sphericalDistance

iD.geo.euclideanDistance should only be used for calculations of 
projected coordinates or display (pixel) coordinates.

iD.geo.sphericalDistance calculates approximate geographical 
distances, accounting for distortions at higher latitudes. This 
can be used for determining the nearest node (operations.Delete,
actions.Circularize) or relative length comparisons (actions.Split).
Clean up
fix test case "does not delete tagged nodes" of iD.actions.Straighten

The nodes.sort() statement caused some trouble in older browsers
such as (FF 20, Chromium 25). Also, the straighten action should
conserve node order. Thus, the sorting made the test weaker than
it had to be.

This just removes the unnecessary sorting.