Uses json instead of deprecated django.utils.simplejson if possible.

Also cleans up views code for less duplication. Style fixes in urls
module, including removal of needless * imports.
Refactors views helpers to utils, further views cleanup.
Adds egg files, build and dist directories to gitignore.
Refactors view manager handling into helper function.
Increments version to 1.0.9.1 in order to ensure pip upgrades.
Adds deconstruct() methods to both custom Field classes.

This is necessary for Django 1.7 migrations, in order to serialize these
fields.

Both of this library's Field classes have non-standard keyword
or positional args, and so these fields require their own deconstruct
methods in order be serialized and reconstructed correctly.

Also bumps version number to 1.0.9.2.
Fixes handling of GroupedForeignKey's group_field arg in deconstruct().
Merge pull request #68 from joelcrocker/master

Django 1.7 Compatibility