4 Open all files in binary mode. Output os.linesep instead of '\n'.
7 Add option -I to completely skip (remove) subparts -- no headers, no body,
11 Extend options -eIi to multipart subparts.
14 Never touch multipart/encrypted and multipart/signed (but allow -I).
17 Convert dates to the current locale and timezone (with an option?)
20 Allow -d and -p accept shell-like patterns and/or regular expressions:
21 -d content-*,-content-*-encoding
24 Add option --save-as='%format' to generate names for --save-* files. Develop
25 a DSL to conditionally use values of headers, parameters and the counter.