The 6Dg sets its power demand in 5% steps, while the universal controller
(EIMCtrlType 3) ramped it continuously. A new optional UCList header key,
CtrlValStep (e.g. 0.05), makes the setting move in whole steps: one at once
when the controller is moved onto a raising or lowering position, then one
each time SpeedUp / SpeedDown covers a step, stopping at the position's set
value. Without the key (default 0) nothing changes.
Data (SVN, optional, after this): add CtrlValStep=0.05 to the UCList: line
of dynamic/pkp/6dg_v1/6dg.fiz (its variants include it).
(eu07/maszyna#412)
