We now accept symbolic and numeric mode strings using the
--mode or -m option for install. This is used either when
moving files into a directory, or when creating component
directories with the -d option. This feature was designed
to mirror the GNU implementation, including the possibly
quirky behaviour of `install --mode=u+wx file dir`
resulting in dir/file having exactly permissions 0300.
Extensive integration tests are included.
This chnage required a higher libc dependency.
Add install utility skeleton source, based on
mv, including the getopts setup mirroring
GNU's `man install` documentation. Also
add a single test and build system code.
