extensions_framework: inherit property_group_renderer from bpy.types.Panel, works with manual RNA registration

extensions_framework: remove addon_register_class from init_functions return; can use @AddonInstance.addon_register_class directly

extensions_framework: Add optional bl_info parameter to Addon class contstructor, useful for making bl_idname and bl_label strings for versioned addons

extensions_framework: Removed old and empty classes, added a more useful Addon class for register/unregister management

extensions_framework: don't use caching checks in init_properties when using ef_initialise_properties - addons using this interface will now enable/disable/enable correctly in the same session.

extensions_framework: added ef_remove_properties function as a complement to ef_initialise_properties

extensions_framework: changed ef_initialise_properties function to not register the class with RNA, added another function ef_register_initialise_properties that does both.

extensions_framework: added ef_initialise_properties class decorator to initialise declarative_property_groups at declaration time instead of requiring a potentially huge class list in the addon __init__ file

update_tag() tags for depsgraph update only, update() executes normal recalculation and creates edge data.

start of add object framework. mainly a copy from add_object_utils.py plus some convenience functions atm. when in a more robust state discuss with ideasman if to remove add_object_utils.py