sql_gen.py: CompareCond.to_str(): If left_value has been renamed as a NamedCol, unwrap it

sql_gen.py: Join.to_str(): Fixed bug where USING should be used if all columns are join_same_not_null, rather than join_same, because USING uses plain = for comparison. sql.py: put_table(): input_joins now can use sql_gen.join_same_not_null in order to use USING syntax.

db_xml.py: put_table(): Output debug messages with a level of 1.5 to match sql.put_table()'s level for summary messages

bin/map: Fixed bug where verbosity needed to be 1 outside of test mode so that profiling and errors stats would be printed at end of import. Verbosity defaults to 0.5 rather than 1 in test mode so profiling and errors stats do not clutter up the test output when running automated tests.

bin/map: Only display verbose_errors in test mode, but with any nonzero verbosity. They should not be displayed outside of test mode because verbose errors make the log files huge.

bin/map: Renamed verbose param to verbosity because it's now a number, not a boolean

bin/map: Removed no longer used debug param (verbose=2 is used instead)

bin/map: Fixed bug where verbose_errors' default value depended on debug var, which was not yet set. Removed verbose_errors param and instead turn verbose_errors on whenever verbosity >= 1. Verbosity defaults to 1 in test mode.

bin/map: Logging: Don't set sql.run_raw_query.debug, because it is not used anymore (sql.connect(log_debug=...) is used instead)

bin/map: Logging: Print debug messages (level > 1) prefixed with their level, to distinguish higher- and lower-level debug messages