validation/aggregating/*/*.sql: renamed views to match the current naming scheme in the DB. these files still need to be kept up-to-date because there are some queries that haven't been implemented yet, and therefore exist only in these files, not the DB.

schemas/util.sql: ifnull(): use COALESCE instead, because it turns out that MySQL's IFNULL is just a special case of this

added inputs/bien2_traits/validations.sql, from validation/aggregating/traits/BIEN2_traits/bien3_validations_traits_original_mysql.VegCore.sql

inputs/input.Makefile: $(svnFilesGlob): added validations.sql

bugfix: validation/aggregating/traits/BIEN2_traits/bien3_validations_traits_original_mysql.VegCore.sql: added util to search_path so that IFNULL would link to util.ifnull()

schemas/util.sql: added ifnull(), equivalent to MySQL's IFNULL (Postgres auto-lowercases the name)

lib/sh/util.sh: stderr_matches(): documented that the purpose of not redirecting fd 2 back to fd 2 is to allow log-filtering out an otherwise-confusing benign error

lib/sh/util.sh: ignore_err_msg(): documented that unlike `|| true`, this suppresses only errors caused by a particular error message, rather than all error exit statuses

bugfix: lib/runscripts/validations.pg.sql.run: updated table match pattern to include the type prefix that validations queries now contain

bugfix: lib/runscripts/validations.pg.sql.run: --table: need to include explicit schema so that matching tables from other schemas are not included