cmd/ftp: exit cleanly on Ctrl-C
cmd/ftp: exit cleanly on Ctrl-C

bup ftp currently does not handle KeyboardInterrupt exceptions.

Simply call handle_ctrl_c() at the beginning of the file to make the
command exit without a stacktrace.

gevaerts/bup,apenwarr/bup,apenwarr/bup,mhoeher/bup,gevaerts/bup,mhoeher/bup,jbaber/bup,tjanez/bup,apenwarr/bup,jbaber/bup,ToxicFrog/bup,mhoeher/bup,mhoeher/bup,pombredanne/bup,ToxicFrog/bup,jbaber/bup,ToxicFrog/bup,tjanez/bup,jbaber/bup,pombredanne/bup,gevaerts/bup,ToxicFrog/bup,tjanez/bup,ToxicFrog/bup,jbaber/bup,tjanez/bup,pombredanne/bup,tjanez/bup,tjanez/bup,pombredanne/bup,mhoeher/bup,mhoeher/bup,gevaerts/bup,jbaber/bup,pombredanne/bup,pombredanne/bup,gevaerts/bup,apenwarr/bup