inputs/GBIF/raw_occurrence_record/run: tables: set ENGINE to MyISAM and DEFAULT CHARSET to utf8 to match the other GBIF tables. (note that MyISAM is not the default, but is needed to avoid row sort order problems and other issues with InnoDB.)

inputs/GBIF/raw_occurrence_record/run: plant_fraction.table/make(): in remaking mode, drop the table first

inputs/GBIF/raw_occurrence_record/run: plant_fraction.table/make(): only create and populate the table if it doesn't already exist, to avoid clobbering existing data. the noclobber functionality uses new skip_table(), which is the table analog of require_not_exists().

lib/runscripts/table.run, table.run: use new db_make.sh

added lib/sh/db_make.sh that includes both db.sh and make.sh, and will eventually contain DB-related make commands

lib/sh/db.sh: added skip_table(), which prints an already_exists_msg for tables

lib/sh/util.sh: already_exists_msg: undid r9621 because the `|| return 0` should actually always be explicitly specified by the caller, to make it clear that the function will be aborted

lib/sh/util.sh: already_exists_msg(): added alias for use as an error handler. note that ..._not_exists() functions should continue to use the "already_exists_msg" function instead to preserve the exit status.

lib/sh/util.sh: added already_exists_msg() and use it instead of manually generating the die() call

schemas/my.cnf: added innodb_file_per_table so each InnoDB table will get its own file. this should also allow databases with InnoDB tables to be manually renamed.