Improve behaviour of admin module in containers

[alexandrecuer]

1. The admin module is very verbose as it complains with iostat and systemctl
   
2. It is not possible to upgrade the modules which have been modified from the admin module UI
   
   emoncms cannot be upgraded but this is because in the container, the emoncms doc has been deleted, but the doc should be in a distinct repo
   for the core, it is not really a pb as normally you change the container version when you want to test a new version of emoncms
   for the modules, you should have the ability to change version or to test the master

corrected :

• postprocess : adapt model and shell script so they also work in container emoncms/postprocess#32
• admin : Adapt admin model for a correct behaviour in container emoncms/emoncms#1917
• admin bug correction : Readjust admin model to work with BOTH standalone & original containers emoncms/emoncms#1918
• sync : adapt shell script so it also works in container emoncms/sync#40
• backup : adapt shell scripts to work in container emoncms/backup#83

[alexandrecuer]

• feedwriter : if deactivated at startup -> admin module dont detect right now
• Emonscripts : adapt so when you update module like sync or backup, it does not run install.sh which uses sudo
• when using on jetson nano, admin module tries to read on /sys/devices/virtual/dmi but there is no dmi on jetson nano ?

[alexandrecuer]

the tags

Backup : 2.3.4-4-g42073e8
Postprocess : 2.4.7-25-g53f06b7
Sync : 3.2.0-4-g77e8a5b