* perform json_encode() on memcached app $response data to match update_application() string parameter
* return raw snmp_get result for memcached response data during update_application()
* feature: Added app_state support for applications #5068
* moved schema file 173 -> 174
* Re-arrange code
* added device_id to dbUpdate call
* updated function + missing apps
* Rename 174.sql to 176.sql
* Remove $device, it is unneeded when updating. Rename update_applications() -> update_application()
* Some apps can return simply 0
* feature: Allow customisation of rrd step/heartbeat when creating new rrd files
* revert defaults
* added docs + webui config option
* Move RrdDefinition to an Object to make them easier to create and remove the possibility of typos.
* Fix style/lint issues and missing use statements
* 3 more missing use statements
* updated doc + moved schema file
Use data_update instead of rrd_update/rrd_create and influx_update
Centralize rrd file check so we can check against a remote rrdcached server too
Use rrd_name() to generate rrd file names
