Handle deleting / moving nodes that have been previously recorded

[hallahan]

There are two approaches:

1. Just enable deleting nodes that are being created during the current session.
2. Delete OSM Nodes that are both from the OSM API and that were created in previous sessions. Handle this accordingly.

Obviously, option 1 is easier. Option 2 would require further logic with the ODK Backend (Ona).

Part of POI Sprint tracked by master issue #31

[hallahan]

This affects moves too, since a move of a previous edit might be disrupted as well.

[hallahan]

I'm going to remove the delete functionality altogether in OpenMapKit Android. It doesn't lend well to the ODK workflow. For a full-fledged OSM editor, obviously delete is essential. However, when you're filling out an ODK form, having the response include an OSM edit that is a delete is confusing, because the ODK response is an add, but the contents is a delete.

I think that's too confusing and should not exist. I'm going to take out delete. Deletes should be done on the QA stage in POSM server. When doing a field survey, let's just allow adds and modify.

Also, the ODK Aggregate 1.0 workflow is really only an additive system. ODK 2 will be taking modify and delete and use changesets with the server in a distributed way. Doing this in 1.0 will always be cludgy, and we really don't have to have this anyway (to accomplish what we need).

[hallahan]

See #99

[hallahan]

We're removing delete functionality in the app per #99