preferences: allow to disable the testsuite

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
service: give per app service a dedicated handler

In very rare cases the per app service would crash in a
very strange manner. In my oppionion its caused by the
looper code and how it is handled.

Trying a slightly different approach by giving the thread
a dedicated Handler to work with.

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
helper: settings: apply correct file path

Both values would be not set by either the set on boot
feature or a profile.
Fix the wrong file paths.

Signed-off-by: Blechd0se <alex.christ@hotmail.de>