[Developers] /architecture schema changes

[brendan]

1. properties that should be marked unique properties

/architecture/structure/height_meters
/architecture/structure/construction_started (date)
/architecture/structure/closed (date)
/architecture/building/floors
/architecture/building/floor_space_square_meters
/architecture/skyscraper/height_with_antenna_spire_meters

Currently, these are *not* set to be unique in the schema, which  
doesn't make much sense and prohibits doing a mql sort (which would be  
a nice thing to do)

2. to be removed
   /architecture/house/height_meters
   /architecture/building/height_meters
both are functionally redundant (with /architecture/structure/ 
height_meters)

I will make these changes pretty soon (and do some related minor data  
updates). I don't know of anyone who would be affected by this change.  
If you are chime in...

thanks,

Brendan