Ignore Eclipse .settings.
Add Subscription model and data migration to copy CurrentSubscription
records.
Replace sync_current_subscription() with sync_subscriptions().
Switch to using Subscription model in the admin.
Change implementation of has_active_subscription() and fix tests that
depend upon it.
Introduce setting to indicate whether multiple subscriptions are to be
allowed.
Revised implementation of subscribe() and cancel_subscription()
supporting single and multiple subscription modes.
Replace references to CurrentSubscription model and to
Customer.current_subscription.
Remove CurrentSubscription model and add Customer.current_subscription
property.
Merge branch 'master' into multiple-subscriptions
Merge branch 'master' into multiple-subscriptions
Implement backwards data migration to recover CurrentSubscription table
from Subscription table.