Support prefunding _before_ renewal window

[jason-c-child]

These changes allow pre-funding a name renewal before the renewal window opens. It removes the window check (commented out in case it is desired to reenable in the future...this could potentially be converted into a sudoparam and controlled via gov).

NOTE: there are consequences to this action. Take the following scenario:

1. name renewal is pre-funded
2. renewal window opens 30-days before the renewal deadline
3. valid_bid is made on the name
4. pre-funding amount is > 5% of valid_bid
5. renewal deadline comes, end blocker runs
6. name is renewed
7. excess pre-funded STARS are not returned to the pre-funder

im not sure if this is good or badddd...it just is what would happen. the owner can always refund the excess STARS...however it will not be automatic....