Modified pycogent_backports/usearch.py to correctly pass HALT_EXEC for usearch_qf (5.X) code.  Also fixed typo in scripts/pick_otus.py
Modified check_id_map.py to 1.  allow suppression of html generation and 2.  add warnings for empty fields before the Description column
Merge pull request #924 from walterst/check_id_map_columns

Check id map columns