Reformatting of attribute extension code

See merge request !14

Merge branch '2021-04-02T17.33.12-branched_from_master-Adjustments_for_attribute_wrapper' into 'master'

Adjustments and fixes for attribute_wrapper merge

See merge request !12

Merge branch 'master' into 2021-04-02T17.33.12-branched_from_master-Adjustments_for_attribute_wrapper

Resolve #2021 "03 16 branched from master elk stack"

See merge request !7

# Conflicts:
#   docker-compose/lofar-device-base/Dockerfile
Merge conflict due to additional sudo

Add missing \

See merge request !13

Merge branch '2021-04-02T12.40.08-branched_from_master-Add_restart_option_to_dsconfig' into 'master'

Add restart on-failure option to dsconfig

See merge request !11

Resolve #2012 "03 29 run containers as user"

See merge request !6

Use proc fs to access sysctl values, to be able to query whether the variables we want to write are exposed and writable at all.

Merge branch '2021-04-02T11.03.46-Branched_from_master-Add_get_internal_attribute_history_function' into 'master'

Add a convenience func to retrieve the internal attr. hist.

See merge request !10