display "i" for interview whenever circle is visible
add index attribute to waltzLocations

Makes it easier to find related objects by starting
with a location.
return locationsForWaltz() sorted by movement
4 new relational functions

waltzesForLocation(loc)

movementsForWaltz(waltzNum)

resetLocationMovementIndiciesForWaltz(waltzNum)

locationIsPartOfWaltz(loc, waltzNum)
multiple movements@loc: fix sequencing bugs