We got bad performance degrading as the number of terms increased.
Enabling django_debug_toolbar it was easy to see a bunch of queries
getting terms related to items duplicated as many times as items
in the system. Making the api view for listing items prefetch related
terms (and their taxonomies) removes these O(n) queries

The next hidden parameter in the form, which determines the redirect
following an update is set to the 'next' query parameter in the form.
If the query parameter does not exist, the HTTP_REFERER is used.
If neither exist, the user gets redirected to the dashboard.

Add the add item functionality. Also enforce a default value for item-type on forms. While the API allows for items without an item-type, the form's handling of it was inconsistant. Until we have a use case for items without an item type, a default is enforced.

Make the update button first in the code so that html5 browsers consider it the default button when pressing enter.

This is a temporary fix - we should fix this properly by getting
the serializer to format datetimes for us.

Disabling the API urls is a quick fix security measure.  Obviously we'd
want the api urls to exist -- with suitable authentication in a real
system. And it sucks to loose the ability to use the web interface to
the API that DRF provides during testing, so here I'm disabling only
if DEBUG=False

The API urls don't need to appear in the system urls.  They code that
uses the api, including the transport layer, can function without it.
This commit removes all the calculation of correct urls using reverse
(which depends on the ruls being included in the systme urls) and
replaces with just spaces -- which seems to work just fine.

Need to figure out how to get the read-only properties serialized.

Responding to feedback from code review, change the item fixture
to use the create method from transport.items instead of FactoryBoy

If you call get with an invalid item id, you should get a
TransportException that communicates the nature of the failure

Added test and updated body of get to raisae exception on unknown item

Added a simple test for the happy day scenario of getting an item from
/api/items/nn/ and made the test pass by calling the API