Show only mapped rooms in the Schedule

[MaZderMind]

As a conference organize i want the Schedule-View by default to only show the rooms mapped to a stream and respect my room-order

IT should still be possible to override the rooms and sorting with the roomfilter (possibly renaming the property with backwards compatibility)

[saerdnaer]

Current situation:
When no room filter is used:
schedule view displays rooms in order as they appear in the schedule xml

When room filter is set:
schedule view sorts room by name or simular. Most times it is exactly the other way around than one wants it.

[saerdnaer]

@MaZderMind did we fix this issue already?