Support creation of disjoint slots for a given topic, to support the new "scattered" topic layout we plan to use for HK. Change-Id: I9bd382c05234a58a162dbcbb7efced396d0ff7e9
Allow to create topics separately from slots, as we usually don't have the topic room layout until late in Summit prep.
Initial import after cleanup. Previous history lives in https://code.launchpad.net/~ttx/+junk/odsreg