ToDo:
- admin: 
    - fix overview (split device overview, measure overview)
- options for caching (instead of full cache)
- option for show/hide menu in admin bar at top
- dashboard
- charts including:
    + include charts lib to plugin

think of:    
- send mail with csv of data? every week? every month?
- consolidate data to hours average?

done:

- admin: 
    - show last module id, count of devices only active
- option for disable/enable wp_cron (at least for device refresh)
- blacklist module id's for measure synch
- charts:
    + done: WP Business Intelligence Lite
    + show helpful queries in admin