Log Message:
tex-schulmathematik{,-doc}: update to 1.4

package schulma: new package option for not loading icomma

package schulma-physik: new package option for loading circuitikz, new options for
\Messschieber command, new \Kraftmesser command

class schulma-klausur: new command \Formeldokument, command \Gruppen: show
solutions for both groups in sample solution