Add two entries about ports on version upgrades:

• Question 7.8 (ports-major-upgrade)
• Question 7.9 (ports-minor-upgrade)

Submitted by: Matthew Seaman <m (dot) seaman (at) infracaninophile (dot) co (dot) uk>,

		Li <fender0107401 (at) gmail (dot) com>

Reviewed by: keramida, manolis, rene, trhodes