lib/sh/util.sh: log+/-(): setting verbosity: added space around operators to support negative numbers

lib/sh/util.sh: added float functions (esp. float+int()) for dealing with decimal verbosities used by sql.py and column-based import

inputs/GBIF/raw_occurrence_record/run: inputs/GBIF/raw_occurrence_record/run: added check_target_exists so you know why make skipped the file (for other, non-silent targets, it would also avoid make's verbose output when the file exists)

inputs/GBIF/raw_occurrence_record/run: table.tsv/make(): moved making of table.tsv.md5 to separate function

lib/sh/util.sh: $log_fd: indicated that this is only initially stderr (however, the new port will just use stderr if it's not redirected separately)

lib/sh/util.sh: verbosities: 3: added that this includes values of kw params

lib/sh/util.sh: logging: added description of the verbosities available, including what each one does and what it's useful for:

1. verbosities:
2. 0: just print errors. useful for cron jobs.
3. 1: also external commands run. useful for running at the command line....

lib/sh/util.sh: command__set_fds(): echo the >& line at a higher log_level, because this information (i.e. which fd is used by the command for logging) is primarily for debugging and should not normally be printed

inputs/GBIF/raw_occurrence_record/run: table.tsv/make(): also add md5 sum for table.tsv

inputs/GBIF/raw_occurrence_record/run: table.tsv/make(): added back filter kw args, which had gotten deleted in a commit without update (although actually, svn should not allow a commit without update, so the working copy may have gotten corrupted)