2a38b857f7
Diffing on undo steps is a critical performance point of override system, although not required for override itself, it gives user immediate feedback ove what is overridden. Profiling showed that rna path text search over overrides operations was by far the most costly thing here, so now using a runtime temp ghash mapping for this search instead. Seems to give at least 5 times speedup on big production rig.