Creates directory including parent directories, if necessary. Then changes
current working directory to it.
-: **minimal-shell()**
-Spawns a minimally set up MirBSD Korn shell. It references no files in /usr,
-so that file system can be unmounted.
-
: **modified()**
Lists files in current directory, which have been modified within the
last N days. N is an integer to be passed as first and only argument.