This fix enables the usage of bbones easing parameters for edit and pose mode seperately. This allows animators to take advantage of the functionality and may eliminate confusion as the parameters now behave similar to other bbone parameters.
Note that splitting the parameters between the modes effectively creates a new parameter set. Blend files of previous versions do not contain this information and will have the values set to 0 on load. As it broke backwards compatibility for pose mode values anyway, I also took the liberty to rename the easing parameters in some places for consistency (which breaks edit mode values).