inputs/.herbaria/: switched to new-style import, which renamed the columns to the VegCore names. this is done using the commands at wiki.vegpath.org/2013-06-27_conference_call#To-do-for-Aaron > "run the following for each datasource".

lib/sql_io.py: cleanup_table(): don't run the slow ALTER TABLE statement again if the table has already been cleaned up. documented that it is idempotent (and actually was before this change as well).

lib/sql_io.py: added table_nulls_mapped__set(), "__get() wrappers around the corresponding util schema functions

lib/sql_gen.py: added table2regclass_text()

schemas/util.sql: added table_nulls_mapped__get(), which gets whether a table's NULL-equivalent strings have been replaced with NULL

schemas/util.sql: added table_flag__get(), which gets whether a status flag is set by the presence of a table constraint

schemas/util.sql: added table_nulls_mapped__set(), which sets that a table's NULL-equivalent strings have been replaced with NULL

schemas/util.sql: added table_flag__set(), which stores a status flag by the presence of a table constraint

schemas/util.sql: create_if_not_exists(): also ignore duplicate_object exceptions, thrown when trying to add a duplicate constraint

inputs/input.Makefile: %/postprocess: removed no longer used invocation of $*/import (precursor to the runscripts used in FIA)