Adding last runtime to monitoring page

Displays the date/time of the last successful run.

Fixes #431
Merge pull request #438 from TheSerapher/issue-431

Adding last runtime to monitoring page
Add tickerupdate to cron monitoring

Fixes #439
Merge pull request #440 from TheSerapher/issue-439

Add tickerupdate to cron monitoring
(#409) Do not use Memcached if it switched off via config