revset-only: remove usage of `set()` All smartset classes have fast lookup, so this function will be removed soon.

revset: cache most conditions used in `filter` Except when stated otherwise, the condition used in `smartset.filter` will be cached. A new argument has been introduced to disable that behavior. We use it for filters created from `and` and `sub` operations. This gives massive performance boosts for revsets with expensive conditions. revset: branch(stable) or branch(default) before) wall 4.329070 comb 4.320000 user 4.310000 sys 0.010000 (best of 3) after) wall 2.356451 comb 2.360000 user 2.330000 sys 0.030000 (best of 4) revset: author(mpm) or author(lmoscovicz) before) wall 4.434719 comb 4.440000 user 4.440000 sys 0.000000 (best of 3) after) wall 2.321720 comb 2.320000 user 2.320000 sys 0.000000 (best of 4)

baseset: empty or one-element sets are ascending and descending The empty set is full of interesting properties. In the ordering case, the one element set is too.