MaMuT_: use Tobias snippets to set position and brightness for new viewers

Signed-off-by: Jean-Yves Tinevez <jeanyves.tinevez@gmail.com>
MaMuT_: bump to v0.5.0, and put correct dependencies

Signed-off-by: Jean-Yves Tinevez <jeanyves.tinevez@gmail.com>