sql.py: Added pkey_col_()

tnrs.py: tnrs_request(): Added comment that names containing only whitespace characters are ignored by TNRS and do not receive a response row. Our tnrs_db and reimport pipeline handles the necessary re-matching-up by just creating taxonpaths for each Name_submitted, and then letting the data import process on the following import attach to the prepopulated taxonpaths.

tnrs_db: Exclude taxonomic names which have already been scrubbed, by using a filter-out LEFT JOIN on TNRS.tnrs

tnrs.py: max_pause: Changed to 30 min because TNRS sometimes freezes for ~10 min. The freezing usually happens while the data is being uploaded rather than when it's being retrieved, so that the max_pause would not apply, but to be on the safe side, requests should not time out unnecessarily.

tnrs_db: tnrs_profiler: Use iter_text='name' for consistency with tnrs.tnrs_request()'s own profiler's iter_text

tnrs_db: Print cumulative profiling information after every TNRS request, rather than just at the end

inputs/.TNRS/tnrs/tnrs.make: Append to the log file instead of overwriting it, so that the TNRS scrubbing of each import's new taxonomic names can be included in one log file. Echo the command to the log file to identify separate runs.

TNRS-related programs: Use "names" instead of "taxons" for variable names because what's being submitted are actually verbatim taxonomic names, not official references to specific taxa

tnrs.py: tnrs_request(): Profile the TNRS request

tnrs.py: tnrs_request(): Fixed bug where initial_headers needed to be copied instead of just assigned to headers, because initial_headers is a global constant and should not be changed when the Cookie header is added