- provide a default method when 
id = NULL. 
- bug fix: enable nested listing for Missing values.
 
- enable RTF table generation using
metalite_table1_to_rtf. 
metalite_table1: add ... and
header argument (#10, #11), rename type to
record_name. 
- allow user to specify first column width (#9).
 
- error message for formula with more than one group.