schemas/util.sql: map_nulls(): support all datatypes, not just text

schemas/util.sql: added hstore(keys anyarray, value anyelement) and => (anyarray, anyelement) operator to support other element types for hstore

inputs/REMIB/Specimen/create.sql: also remove frameshifted rows with invalid long_deg values

schemas/util.sql: added map_nulls(), a common use case of _map()

bugfix: schemas/util.sql: hstore(keys text[], value text): use new fix_array() so that an empty keys array is made 1-dimensional to match up with the array generated by array_fill()

schemas/util.sql: added fix_array(), which ensures that the array will always have proper non-NULL dimensions

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.