* Insert Keyframe (IKEY) now only shows the menu requesting to choose a KeyingSet to use if there is no active KeyingSet. To get the old behaviour, the "always_prompt" boolean property for the "ANIM_OT_insert_keyframe_menu" operator should be supplied.
* After inserting/deleting keyframes without the menu, a popup menu confirming that the keyframes have been modified is shown. Please note that you do not need to click on this popup.
TODO:
Make the confirmation popup fade out after a fixed time.