inputs/GBIF/table.run: table.tsv/make (): use extern so the MySQL_export command is echoed

inputs/GBIF/table.run: table.tsv/make (): don't make the target if it already exists

inputs/GBIF/table.run: table.tsv/make (): create the file directly rather than using inline_make, so that the command to create the file can use shell functions such as mysql

bugfix: inputs/GBIF/table.run: table.tsv/make (): need to use $(target) (target's path relative to curdir) instead of just the filename, now that make does not change the directory

inputs/GBIF/table.run: moved table.tsv creation to separate table.tsv/make () function

lib/util.sh: echo_stdin (): display the echoed input after leading output of the echoed-to command, by using sleep with a small fractional # of seconds

*{.sh,run}: put functions on one line where possible (and where they are not expected to expand)

lib/local.sh: root_make (): use make () rather than extern make now that make () does not set its own current dir. using make () also automatically enables \$stdout2stderr, which is needed to redirect the echoed make commands.

lib/util.sh: extern (): use exec to ensure that the executed command is in fact external, and not a shell builtin or other type of non-function command. this also simplifies the code because any shell function for the command does not need to be unset.

lib/util.sh: make (): don't change the directory to $top_dir, because paths used by the caller will instead be relative to the current dir (note that in runscripts, paths are generally not absolute because of canon_rel_path ()). this requires manually specifying $top_dir when running make on a physical (rather than inlined) makefile.