update portal-related memory context names and API

When Who What
2018-01-09 19:01:26 Peter Eisentraut (petere) Closed in commitfest 2018-01 with status: Committed
2018-01-09 19:01:26 Peter Eisentraut (petere) Changed committer to petere
2018-01-08 20:31:36 Andrew Dunstan (adunstan) New status: Ready for Committer
2018-01-08 15:28:21 Andrew Dunstan (adunstan) Added adunstan as reviewer
2017-12-26 19:18:03 Peter Eisentraut (petere) Changed authors to Peter Eisentraut (petere)
2017-12-26 19:17:49 Peter Eisentraut (petere) Attached mail thread 53d4ded9-a1bd-98dc-4475-3763c789cdd4@2ndquadrant.com
2017-12-26 19:17:49 Peter Eisentraut (petere) Created patch record