Add Stewardship collection UDFs when creating instances
Return stewardship w/ default mobile fields

Because this is adding a new type of field group that the mobile do not
have the ability to render yet, these changes are only available in v3 of
the API.

This is intended to be the final feature in v3, and all new breaking
changes should be part of v4.
Refactor and centralize permission checking logic
Add meta perms for mobile apps
Fix styling of export modal

fixes #1490 on github
Add constraint to InstanceUser to prevent duplicates

Also adds a data migration to remove any duplicates that snuck in.
Users should only have one InstanceUser per Instance.
Add sort key to default mobile api fields

Because the mobile clients will merge together plot and tree stewardship,
we need to signal to the clients how to sort the merged lists of
stewardship events.

We have no mechanism for changing collection UDF field
definitions at the moment, but if/when we add it this will cause us to need
to take care to not allow the definitions of plot and tree stewardship to
get out of sync
Add neighborhoods to migrator
Return actual JSON, not JSON strings in API instance fields

The data types for collection UDFs were being sent as the string
representation of the underlying JSON.  To fix this, we deserialize it to a
standard python list before reserializing the entire dictionary
Fix lint
Fix Collection UDF date serialization

We were not correctly formatted dates for collection UDFs, which broke the
API for editing, since the server sent dates down in a format it could
not parse.
Fix typo in e5c4f
Pass json and csv through middleware

Fixes #1493 on github
Fix type error crash

fixes #1511 on github

This probably wouldn't occur in production under normal circumstances,
but it's harmless to fix it.
Fix eco request content type

The go-rest dependency of the eco service was updated to use the more
correct application/json content type when posting JSON encoded data

https://github.com/ungerik/go-rest/commit/c3ee1de9e2197fe2812b818f25d2fc59fab9a13e
Add option to not stringify JSON parameters when calling ecoservice