Move views to a package file
Split view logic from view creation
Merge pull request #1368 from steventlamb/topic/refactor_views

Topic/refactor views
Split views to package and factor out lib helpers

There are two broad goals behind this refactor:
* Views got large, and they should be stored in separate files
* Too much business logic is done in treemap/views and should live elsewhere.

It is now easier to reason about views:
* unadorned, view building functions are located in treemap/views/*.py
* view building functions are imported into the top-level of treemap/views/__init__.py where they are wrapped with decorators that make them endpoint-ready.
* urls.py imports functions from the top level at treemap/views/__init__.py with names ending in _view or _endpoint.
* underscore functions are used the way you would expect, and should only be imported by test modules.

Helper functions are now located in treemap/lib/*. It is hoped that this package will grow and swallow up the random files in treemap/*. Maybe it'll eventually even move out of treemap. It would be great if treemap was just the web client app, and was comparable in complexity to the api app, with the business logic living mostly in opentreemap.
Merge pull request #1373 from steventlamb/topic/refactor_views

Topic/refactor views
Extend the detail_link template tag for MapFeaturePhotos
Make photo review work with with MapFeaturePhoto
Fix some copy-paste errors from extracting TreePhoto -> MapFeaturePhoto
Check *all* subclasses of Auditable and Authorizable in FieldPermission

The prior method of checking only leaf subclasses fails now because
MapFeaturePhoto is not a leaf class, but is used directly
Merge pull request #1376 from maurizi/map-feature-photo-review

Map feature photo review
Fix bug with photo review image loading

Approving or Rejecting a photo causes the next image to load, which was
happening even when there was no next page.
Clean up JS on photo review page

 - Break page existence check into named function
 - Look for page elements inside passed in container
Merge pull request #1377 from maurizi/photo-review-bug-fix

Fix bug with photo review image loading
Cleanup decorators

Using currying and higher order plumbing to make the process cleaner and easier to reason about.
Add support for migrating user photos
Cleanup MapFeature views and generalize accordion
Use enhanced decorate syntax everywhere
DRY out views using new syntax
Merge pull request #1378 from steventlamb/topic/view_refactor

Topic/view refactor
Skip migrating missing profile photos

In testing, the migration was crashing when the source photo did not
exist (it is not clear where the source photo went). Instead of crashing
the import it now prints the path to the missing photo and the user info
to the console for case-by-case inspection.