mpd: workaround command termination bug in mpd server v0.18

See Debian bug report #728982 for more information.

Signed-off-by: Adrian C. (anrxc) <anrxc@sysphere.org>
Revert "mpd: workaround command termination bug in mpd server v0.18"

This reverts commit a6a73f47, because the issue was solved in mpd
release 0.18.2. I imported the workaround for historical reasons and
in case someone gets stuck with version 0.18 on his preferred OS
distribution.
init: share timers when possible

We need time to give this a proper test with various usage scenarios;
multiple screens (and thus widget object instances), widgets
suspending and resuming and so on. Most benefits should come from
running on battery power (and if not suspending all widgets but
Battery it self on battery power), with less wake-ups.

Signed-off-by: Adrian C. (anrxc) <anrxc@sysphere.org>
README: enable caching in vicious.widgets.cpu example