Fixed #16594 -- Added wkt 3D support for GEOS geometries

This requires GEOS >= 3.3.0 to function properly. On previous
versions, the Z dimension will simply not appear in the wkt.
Disabled OpenLayers editing for 3D geometries (unsupported).
Fixed #19923 -- Display tracebacks for non-CommandError exceptions

By default, show tracebacks for management command errors when the
exception is not a CommandError.
Thanks Jacob Radford for the report.
Reformatted slightly openlayers.js