allowing for functional infrastructure elements as reference target for limitations of a genericArea

added possibility to reference //topology/netElements/netElement/associatedPositioningSystem/intrinsicCoordinate/@id from spotProjection

added 3.3 references for timetable operationalConnections, vehicleRostering and temporaryRestrictions

added version 3.3 to reference register. all references that existed in 3.2 already have been taken over

railml/version3#617: changed definition of switchIL and movableCrossing references to  infrastructure to also allow reference of netElements