Using CONSTANT_CASE for geometry type
Using PascalCase for geometry enum values

This adds a bit more inconsistency to the library, but we didn't have complete consistency before.  Almost all existing string enum values are lowercase (a couple are camelCase and one is dash-separated).  The closure library isn't consistent either (with case for enum properties or values).  I imagine this could be justified in saying someone could blindly use GeoJSON type values in places, but in the end, you'll need to read the docs before guessing right.
This commit serves no purpose other than helping minimize a diff
Marking the geometry type enum as stable
Merge pull request #1335 from tschaub/geometry-type

Change geometry type enum and mark as stable.
Add a way to delete vertices with the Modify interaction

After this change, vertices can be deleted by simply clicking on
them. This is the same behaviour as e.g. in geojson.io.
Update render intent after inserting a vertex
Do not use the same iterator variable in nested loop