maybe when adding/deleting/extracting fails, go to the next item in the directory
delete files that failed to extract completely
statusbar messages
add modal to all the dialog windows (see showBootInfoCbk() for example)

move posix*Defaults into VolInfo
make size estimate into its own function
improve size estimating
rock ridge special files
make defaults settable (use volinfo)
add functions for checking validity of names when adding