Unsealing/ReSealing Round-Trip

[snadrus]

Problem?
"The cost of an unsealed copy" is a regular pain-point for SPs who happily store multiples of each sealed sector.

Fix?
By adding re-sealing (the input-output inverse of "unsealing") and some minor configuration, keeping unsealed copies becomes the backup of sealed copies, making the data-on-disk size the same for those who serve as for those that who back-up.

Needed?

• Re-sealing
• Configuration: "re-seal when ____"
• An easy way to keep unsealed and sealed sectors apart from one another.