572bc1364c
We were calling BLI_remlink and then BLI_insertlinkbefore/after quite often. BLI_listbase_link_move simplifies code a bit and makes it easier to follow. It also returns if link position has changed which can be used to avoid unnecessary updates. Added it to a number of list reorder operators for now and made use of return value. Behavior shouldn't be changed. Also some minor cleanup.