Issue: License Expiry Changes

To be fair to users who purchase VaultWiki and have to wait for the transaction to clear, or others who just don't use their licenses right away, we should set the expiration date to 1 year after the first download, rather than from purchase as it is now.

Additionally, and this may be more challenging to employ, license renewals should act similarly.

Probably what we need is a flag on the license that says to extend the license period after the next download (but if 0, ignore the field).