Make eco default units "per year"

kwh -> kwh/year
gal -> gal/year
Merge pull request #1296 from RickMohr/eco-units

Make eco default units "per year"
Merge pull request #1297 from RickMohr/update-leaflet-editable-polyline

Give roof polygon point markers a higher Z offset than plot marker
Change the API return schema for instance eco

Previously, eco benefits were returned with a plot as an array. Mobile
applications only needed to know the number of eco fields that would be
included. Now, the eco fields for a plot are returned as a dictionary,
so the instance API must return the keys needed to read from the
dictionary and the order in which those keys should be displayed. I
copied the key ordering from the current web app UI.
Update Co2 stored label

Requested in https://github.com/OpenTreeMap/OpenTreeMap-iOS/issues/129
Merge pull request #1299 from jwalgran/topic/co2-stored-label-update

Update Co2 stored label
Merge pull request #1298 from jwalgran/topic/api-eco-schema-update

Change the API return schema for instance eco
Remove background tree photo, but add it to base.scss for future work
Merge branch 'release' of github.com:OpenTreeMap/OTM2 into release
Fix typo in instance info endpoint
Revert change from PR #1293

This was not a typo. It is a dictionary comprehension.
Merge pull request #1309 from OpenTreeMap/release

Release