Bug 17261: Memcached may not longer be running

Bug 17261: Memcached may not longer be running

If plack is started with memcached, memcached will be considered as
running, even if it has been stopped (or crashed).
This case should be highlighted on the about page.
Note that I am not sure about the consequences of this specific case!

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Katrin Fischer  <katrin.fischer@bsz-bw.de>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>