find.c: add -mindepth, -maxdepth, and document -newer and -depth.
Fix a couple patch bugs concerning error output.
Building busybox from source needs find -not (a synonym for posix's "!").
find.c: Posix wants loop detection.
Rereading posix find.c page: "Specifying more than one of the mutually-exclusive options -H and -L shall not be considered an error. The last option specified shall determine the behavior of the utility."
More find bugfixes.