schemas/util.sql: lat_long_in_new_world(): documented that this includes false positives above and below the New World bounding box, as described in util.bounding_box()

schemas/util.sql: bounding_box(): documented that the geography type stores all edges as arcs of great circles, resulting in the latitude lines bulging outward from the true bounding box. this will create false positives above and below the bounding box.

schemas/util.sql: added lat_long_in_new_world()

schemas/util.sql: added operator @(postgis.geography, postgis.geography). can't use && for this because it only compares 2D bounding boxes (which are geometry objects that do not support geocoordinate wraparound).

schemas/util.sql: added point()

schemas/util.sql: new_world(): removed no longer needed cast to postgis.geography

bugfix: schemas/util.sql: bounding_box(): must use postgis.geography (instead of postgis.geometry) because that handles geocoordinate wraparound correctly

bugfix: schemas/util.sql: bounding_box(): need to explicitly set SRID to make sure the correct value is used

bugfix: schemas/util.sql: bounding_box(): use st_makeenvelope() instead of st_makebox2d() because st_makebox2d() doesn't support geocoordinate wraparound (it is not SRID-aware)

schemas/util.sql: new_world(): removed no longer needed cast to postgis.geometry