items start out minimized, with abbreviated status information

Everything fits on one line this way. Includes a twisty so that individual
items can be opened or closed.
use some unicode triangles for the twisties instead of letters, and tweak the spacing so that the text doesn't move when you click them
factor out the code for updating the brief status/log

Also fixes a minor bug that causes the brief status and log to be lost whever
we recieve the item.update_name message.
Merge remote-tracking branch 'db48x/minimizable' into minimizable
Fix bug in task count.