getopt() already emits warning about unknown option, so if we do that, too,
the result will look like this:

	$ ./ioping -z
	./ioping: invalid option -- 'z'
	ioping: unknown option: -z

Don't warn about unknown option, instead show usage().
Signed-off-by: Kir Kolyshkin <kir@openvz.org>

Needed mostly for distro vendors (.spec writers etc.)

* Makefile: do not strip when installing
Otherwise distros could not produce debuginfo packages

* Makefile: add BINDIR
Signed-off-by: Kir Kolyshkin <kir@openvz.org>

Signed-off-by: Kir Kolyshkin <kir@openvz.org>