bugfix: inputs/GBIF/raw_occurrence_record/run: table.tsv/make(): added check_target_exists so table.tsv would not be overwritten if it already existed

bugfix: inputs/GBIF/table.run: table.tsv/make(): force table.tsv.md5 to be remade (using remake=1) because the table.tsv contents will have changed

bugfix: lib/sh/make.sh: set_make_vars: can't use end-of-line comment in alias because it will comment out whatever is after the alias where it's used. can't just put a newline or ; after the end-of-line comment because the alias's lines will be combined onto one line using ; , so end-of-line comments would not be supported.

lib/sh/util.sh: added pf(), to print a function declaration for debugging

inputs/GBIF/raw_occurrence_record/run: plant_fraction/make(): documented runtime (1 hr)

*.url: mailto URLs: use the standard e-mail dotpath syntax e-mail@host?name.date.subject.(attachment) (vegpath.org/wiki/Global_IDs#Resource). populated missing fields (e.g. name, subject) where needed.

*.url: mailto URLs: ensured that they are proper URLs with the mailto: protocol

lib/sh/util.sh: to_file(): exc handler that rm's file: unset redirs so it isn't used in the rm cmd

inputs/GBIF/raw_occurrence_record/run: herbaria_filter/make(): removed no longer needed explicit clear of $remake, which is now done by make.sh instead

lib/sh/make.sh: set_make_vars: don't progagate remake to prerequisites, so that remake=1 only applies to the outermost target rather than forcing every prerequisite to be remade, too