inputs/REMIB/Specimen/create.sql: moved filtering out of frameshifted rows to postprocess.sql, where it can happen in an idempotent DELETE. this allows filters to remove additional rows to easily be added on top of the existing filters, without needing to remake Specimen (which takes a long time, because of the many stage I derived columns that get added). the logical inversion inherent in the DELETE condition has been factored through rather than wrapped in NOT (...), because removal of frameshifted rows is more accurately specified as the detection of specific patterns that indicate frameshifting rather than the validation of all fields.

bugfix: schemas/util.sql: not_empty(anyarray): array_length() now refers to different functions, with different semantics, depending on whether util is in the search_path. this necessitates explicitly selecting util.array_length() and switching to its semantics (ARRAY[] -> 0 instead of NULL)

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.