update docstring styles
add .env to gitignore
add util for turning an instance back into a queryset
add decorator so actions work on objects or querysets
fix django 1.5 is special in how you get the model

fixes the error:

    AttributeError: 'Options' object has no attribute 'model'
use the decorator in the example project

also fix typos in the short descriptions
add docs for takes_instance_or_queryset
tweak format of limitations section of readme
Merge pull request #5 from crccheck/double-duty

Allow regular actions written for the admin to also work for this package