this is a simplicifcation for the ppms driver - the derivation of a changecmd from a querycmd is moved to CmdHandler.__init__ - the special treatment of handlers when writing configured parameters has moved to CmdHandler.write - introduced Drivable.isDriving, changed Module.isBusy Change-Id: I8862ecda9c8cc998bb018bd960f31c9488146707 Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/22033 Tested-by: JenkinsCodeReview <bjoern_pedersen@frm2.tum.de> Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>