A long requested feature has been to have objects appear in alphabetical order in the animation editors, so that it is easier to find where they occur. This commit implements support for this. The main sticking point has been the performance impact of having this sorting happening all the time (as the actual list of "bases" cannot be modified, as the old depsgraph still needs random-looking unsorted order of objects for scheduling updates). However, it recently occurred to me that perhaps by restricting it to the one case where the ordering actually matters (i.e. when we're getting the channel list for drawing all channels, vs operating on them), and adding a toggle to turn the sorting off in heavy scenes when it might bog down things, that it will probably be acceptable enough in general. Furthermore, if things get really bad, we can investigate putting in place some sort of caching scheme for this too - though hopefully the new depsgraph will make that unnecessary (i.e. it doesn't sort the bases directly anymore).