schemas/util.sql: added empty_array(), for constructing proper empty 1-dimensional arrays whose dimensions are not NULL ( {}::text[] does not do this)

bugfix: schemas/util.sql: array_length(anyarray): need to call util.array_length() instead of just array_length() (which uses pg_catalog.array_length()) so that empty arrays will be returned as 0 instead of NULL. note that for some reason, adding `SET search_path=util` to the function does not have the same effect.

inputs/ACAD/Specimen/postprocess.sql, inputs/ARIZ/omoccurrences/postprocess.sql: removed unnecessary "" around keys/values. "" are required in hstore input syntax in approximately the same places as they are in XPaths (around values containing spaces or special characters).

inputs/ACAD/Specimen/map.csv, inputs/ARIZ/omoccurrences/map.csv: removed derived columns, which cause an error when trying to rename a table that does not yet have the derived columns added. this error will not be noticed locally if the derived columns were added before switching to new-style import, but will be noticed on vegbiendev.

inputs/ARIZ/: switched to new-style import, using the steps at wiki.vegpath.org/Switching_to_new-style_import#stage-I-source-specific > "run the following for each datasource"

added inputs/ARIZ/omoccurrences/postprocess.sql

inputs/ARIZ/omoccurrences/: translated single-column filters to postprocessing derived columns, using the steps at wiki.vegpath.org/Switching_to_new-style_import#stage-I-source-specific > "translate single-column filters to postprocessing derived columns"

bugfix: schemas/util.sql: _map(map hstore, value anyelement): need to cast result to unknown to support types that don't have a cast directly from text

schemas/util.sql: added _map(map hstore, value anyelement) to seamlessly map types other than text (by casting back and forth between text and the value type)

inputs/ACAD/: switched to new-style import, using the steps at wiki.vegpath.org/Switching_to_new-style_import#stage-I-source-specific > "run the following for each datasource"