progress bar for file conversions

[rroutsong]

progress bar for file conversions

possibly with dlang ncurses wrappers:
https://github.com/adamdruppe/arsd/blob/master/terminal.d

associated links:
http://code.dlang.org/search?q=ncurses
https://forum.dlang.org/thread/mhouqrkhqdcjvffzbksw@forum.dlang.org