MyConversations: releases and other announcements

[Laird]

MyConversations version 1.2.3, soon to be released, has been installed on this board and on the Psience Quest board for live testing. It is mostly a maintenance and bug fix release with only one significant new feature: the list of group participants in the conversation compose form now auto-updates when a (different) group is selected. The full set of fixes will be documented on release.