function for resolving paths.
Make pathadj() no longer warn about symlinks. Symlinks in /dev are
regularly used in several places like LVM . The warning was also
only visible when calling a mount_* command directly as mount(8)
itself would resolve the path witout warning before passing it to
a mount_* command.
distinct and allowing this makes certain useful tasks possible, such as
fixing an unpopulated /dev while a tmpfs is mounted over it.
However, require the paths to be different, as mounting a path directly over
itself has the side effect of causing any other mount points within that path
to no longer be accessible, and is difficult to unmount when done on /.
systems just checked != 0, breaking MNT_GETARGS. Others worked with < 0,
but make them check against -1 too for consistency. And sprinkle some
stylish line wrapping where appropriate.
* make static all symbols which do not need to be exported
* rename main() to mount_FOO()
* new main() now just calls mount_FOO(), main() is only compiled in if
MOUNT_NOMAIN is not defined
* a_gid(), a_uid() and a_mask() were put into ../mount/fattr.[ch], local
versions removed
