bin/tnrs_db: removed unused imports

bin/tnrs_db: cumulative_tnrs_profiler: use tnrs.tnrs_request()'s new cumulative_profiler param instead of doing the profiling manually. this also ensures that there isn't extra time between when the cumulative profiler starts/stops and when the per-request profiler starts/stops (because Profiler's new add_subprofiler() method is used).

lib/tnrs.py: single_tnrs_request(): added support for a cumulative profiler using the cumulative_profiler kw param

lib/profiling.py: Profiler: added add_subprofiler(), for use with cumulative profilers

lib/profiling.py: Profiler: added add_time() and use it instead of `self.total +=`

bin/tnrs_db: tnrs_profiler: renamed to cumulative_tnrs_profiler to distinguish it from the tnrs_profiler used by tnrs.tnrs_request(), which just profiles the current request

bugfix: bin/tnrs_db: cumulative profiler: use len(names) instead of this_ct (cur.rowcount) in case the actual # rows fetched differed from the rowcount

lib/tnrs.py: repeated_tnrs_request(): renamed to tnrs_request() since this is the function that should usually be used, to ensure that debugging information is output in the case of an error. (the TNRS request must be made again to output this information.)

lib/tnrs.py: tnrs_request(): renamed to single_tnrs_request() to distinguish it from repeated_tnrs_request()

bin/tnrs_db: removed no longer used $wait flag (which caused tnrs_db to wait max_pause for new rows to be added), because tnrs_db is now invoked automatically after each import by the import_scrub target (in inputs/input.Makefile) and does not need to run as a daemon. note that when scrub is invoked, it is possible that a previous datasource's import has already scrubbed the names for this import, because tnrs_db runs until all rows in tnrs_input_name are scrubbed....