DRY up stylesheet URL resolution.
Update PM view on theme/settings changes.
Reply to PM is an action on the message itself.
DRY up date formatters.
Document keys for dictionary given to posts view.
More private message parsing.

Split into folder parsing (list of messages) and message parsing (single
message).

Test PM parsing.

Fix compiler warnings in parsing tests.
User model can have multiple sent/received PMs.

Messed up the model the first time :-(
Parse regdate in local time zone.

Turns out SA does this.
Fix test assert.