sql_io.py: cast(): Always convert exceptions to warnings if the input is a column or expression, even if there is no place to save the errors, so that invalid data does not need to be handled by the caller in a (much slower) extra exception-handling loop

sql_io.py: put_table(): MissingCastException: When casting, handle InvalidValueException by filtering out invalid values with invalid2null() in a loop

sql_io.py: cast_temp_col(): Run sql.update() in recover mode in case expr produces errors. Don't cache sql.update() in case this function will be called again after error recovery.

sql.py: Generalized FunctionValueException to InvalidValueException so that it will match all invalid-value errors, not just those occurring in user-defined functions

sql_io.py: put_table(): Removed no longer used sql.FunctionValueException handling, because type casting functions now do their own invalid value handling

db_xml.py: put_table(): Subsetting in_table: Call put_table() recursively using put_table_() to ensure that limit and start are reset to their default values, in case the table gets partitioned (which needs up-to-date limit and start values)

sql_io.py: put_table(): mk_main_select(): Fixed bug where the table of each cond needed to be changed to insert_in_table because mk_main_select() uses the distinct table rather than the full input table

sql_gen.py: with_table(): Support columns that are wrapped in a FunctionCall object

sql_gen.py: index_cols: Store just the name of the index column, and add the table in index_col(), in case the table is ever copied and renamed

Moved error tracking from sql.py to sql_io.py