Switch from X Upgrade to X subscription.
Do not complain if the user just canceled.
Push version to 7beta2 for subscription trial version.
Fix: do really not complain if user just cancelled subscription process.
Fix unsubscribing not disabling X features.
Bump version.
Move key getter to BillingActivity.
Notify about subscription state changes.
Set more attrs on the expired notification (auto cancel, lights, ticker, prio).
Bump version.
Merge branch 'subscription' into beta
Preliminary changes for 7beta2.