bugfix: *run: overriding targets: use new self_make to properly progagate the $remake flag to the overridden target, so that the target itself is not skipped

lib/sh/util.sh: to_file(): added del= flag to prevent the file from being auto-removed on error (e.g. to preserve a partial result, which normally would be removed)

lib/sh/make.sh: added self_make(), which progagates the $remake flag (normally it is not progagated, because prerequisites should not also be remade)

lib/sh/util.sh: usage comments: when there is a descriptive comment on the same line as the usage, prepend it with # (as if it were an end-of-line comment) instead of enclosing it in (), to make it visually obvious that it's a comment and not part of the usage commands

lib/sh/util.sh: added all_funcs(), which lists all declared functions

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)