sql.py: put_table(): mk_select_(): Fixed bug where it was sometimes being called without distinct_on, causing it to return a different # of rows. Renamed mk_select_() to mk_main_select() for clarity.

sql.py: put_table(): Do inserts and selects in a loop so that it will keep retrying the operation with additional constraints until it succeeds

sql.py: put_table(): mk_select_(): Fixed bug where order_by needed to be None because otherwise it wouldn't match the distinct_on cols if they were specified

sql.py: put_table(): insert_(): Fixed bug where distinct_on was not passed to mk_select_()

sql.py: put_table(): mk_select_(): Fixed bug where distinct_on needed to be passed as a keyword param

sql.py: put_table(): insert_() and mk_select_() take distinct_on param

sql.py: put_table(): Factored out code that inserts into pkeys table into run_query_into_pkeys() helper function

sql.py: mk_select(): Implemented DISTINCT ON according to the distinct_on param

sql.py: mk_select(): Added distinct_on param to set the columns to SELECT DISTINCT ON

sql.py: clean_name(): Convert names to lowercase so that PostgreSQL will behave the same whether the name is escaped with "" or not. This will help avoid bugs in code that uses temp tables created by the sql module.