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.

fix text navigator for updates in API, this also wasnt working because it called operator from draw function (less recent api change).

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

from Filiciss Muhgue (filiciss)
fixes [#25997] Export to X3D reports error TypeError: 'NoneType' object is not scriptable.

Fixed some minor formatting issues and added support for engines that do not natively recognize the AnimTicksPerSecond template.

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

API: 34650
fix: x-offset in one mapping of Alphamap was inverted

from Dominique Lorre with own modifications. 

use settings as suggested by John Coady (jdc)

fix for recent mathutils updates. note that the logic here is confusing and Im not sure why the original bone matrix us used at all.

- changed support level to OFFICIAL
- fixed missing last point at building Mesh-ARCs (by pildanovak)
- fixed for changes in API and mathutils by campbell

bugfix [#25903] Export to X3D should provide relative path with forward slash for subdirectories in url of ImageTexture