multiview: from review - rename result_actview_set to active_view_set
multiview: from review - unify RE_BlenderAnim and RE_BlenderAnimViews
+ cleanups to minimize the changes against trunk
multiview: from review - add define for pass name in make_pass_name + chan_id back to 8

This was from when I tried to have multiview in a single pass
multiview: from review - openexr_api.cpp clean ups
multiview: from review - change Image Node dynamic enum
(using All instead of Placeholder)