index_model_field for producing a lookup dict from a field value to a pk for any model
blank_none option, count_lines function, ignore_errors, progressbar

+ blank_none option when producing dict of values from sequence of values, to allow none=False, blank=True, django string fields (CharField, TextField)
+ count_lines from slow stack overflow implementation
+ ignore_errors to allow import of large CSV files to complete even if errors in value coercion
  only output of failed line numbers is to stdout (not recorded and returned)
+ progress bar for more verbose progress indication