adapted check_alignment because new inheritence system
new functions: 'switch_to_base_group' and 'switch_to_original_group'
refactor for more readabilitly
new functions: 'get_group_with_its_sp_obj'
refactor (because of the just introduced get_group_with_its_sp_obj-function)
cover all cases regarding orientation (horizontal and/or vertical set or not set)
new operators: set valid/horizontal horizontal to false
removed get_oa_group completly
get_group_with_its_sp_obj returns (None, None) if either simp or impl is defined
opengl-viewport to close-error-bug closed
moved get_group_with_its_sp_obj moved to common.py
moved get_sp_obj and get_sp_obj_from_base_id to editor.common because it should only be used in the editor
removed legacy code: object_editor.py
renamed last group_ids to oa_ids and (group_id for UI to category_id)
added editor/common.py to git
next_unused_*: use only groups with that have objects