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.
correct number of tasks on update
don't trim first word of the brief log message

Decided to use the trimLeft() method rather than a regex in order to avoid
this sort of mistake in the future.
items default to uncollapsed, with a checkbox to collapse them all

The user can still collapse and uncollapse them individually, and the
state of the checkbox is remembered in localStorage so that it can be
restored across sessions.
show rsync progress in the main log as well as the brief log

rsync puts the \r at the end of every line, rather than the beginning,
so processCarriageReturns dumped the whole line. The brief log is
processed slightly differently so it wasn't affected.

fixes #8
Merge pull request #18 from db48x/minimizable

merged