Updated Membership.is_forever method to only evaluate expiration date and not status of membership.
Removing extra checks in Membership.can_renew method.  These checks have already been done by previous functions.
PEP8 memberships/views.py
Refactoring the evaluate a superuser when displaying available membership types on a membership form.
Updating doctoring on get_membership_type_choices function.
PEP8 memberships/models.py and memberships/forms.py
Updating logic when displaying a membership type on the membership form. We evaluate every membership type using your current memberships and their renewal periods.
Misspelling in memberships/views.py
Formatting doctoring on MembershipDefault.get_price method.
Updating the way we save membership form prices.  Getting price per membership type.
Defaulting to "join" when a membership form is submitted.
Commenting out the save_invoice on approve because it's reseting everything for paid invoices.
convert range() to xrange() for efficiency.
PEP8 memberships/managers.py
Specify django-simple-cache to 0.3.6

The release 0.3.7 requires Pillow which we don't want to include right now.
Merge branch 'master' into 26_recurring_payments_confirmation_text
Added fixes