Icon update
Add jQuery
Add a fix CORS POST prototype (disabled)
Preliminary CORS documentation
Add JSZip to build
Use KMZ format for e-mail sending
TODO update
KML notes to README
Revise email body: KMZ
Add degree sign to heading
Trail length (2d/3d) calculation primitives

These don't work well for the active segment.  For the active segment
it would make more sense to cache a partial length up to a certain
index, and resume computation from that index (and cache the new
result, up to that index).  When a segment is simplified, the caches
need to be flushed.
Periodic trail length updater; click len = update

This will be replaced by live updating which requires length caching
"up to index X".
TODO update