Authenticate species endpoint if needed
Don't include the "udfs" dictionary

These fields are already included as "udf:XXX"
Disable automated unit scaling

Previously units were always scaled at compile time which led to code
like this:

t = Tree.objects.get(pk=1)
t.diameter = 1  # units set to "feet"
t.save()

t = Tree.objects.get(pk=1)
print t

>>> 12  # Unscaled and in "inches"

Now these transforms must be done explicitly with:
    convert_to_database_units and convert_to_display_units
Support a custom set of mobile api fields
Include eco benefit detail in API responses

I needed two additional pieces of information to allow the iOS
application to correctly display eco benefits on a plot detail view.

1. The instance details need to declare the eco fields that can be
   displayed.

2. The plot details need to include the configured currency symbol in
   the formatted amount saved field. This keeps all the currency
   formatting on the server side.

Adding the currency symbol to the formatted result required updating the
app templates so that they did not end up displaying the currency symbol twice.
Merge pull request #1128 from jwalgran/topic/add-eco-detail-to-api

Include eco benefit detail in API responses
Merge pull request #1129 from azavea/topic/misc-api-changes

Topic/misc api changes