more descriptive output filenames
log_dvd_info() before prompt_input_output()
get_out_paths(): return absolute paths
update script descriptions in main.py and README.rst
fix bug in BG.log_output_info()
add user prompts to izdvdbg/izdvdmenu and choice to display menu image in izdvd user prompt
fix bug where --dvd-format not present in dvd_opts
add more menu attrs to DVD()
utils.log_items(): make text representation of None more visible