revset: added isascending and isdescending methods to smartset classes This methods state if the class is sorted in an ascending or descending order We need this to implement methods based on order on smartset classes in order to be able to create new objects with a given order. We cannot just rely on a simple boolean since unordered set are neither ascending nor descending.

revset: added sort method in addset We need this method to duck-type generatorset since this class is not going to be used outside revset.py and we don't need to duck-type baseset. This sort method will only do something when the addset is not already sorted or is not sorted in the way we want it to be.

revset: added reverse method to addset This method is needed to duck type generatorset.

revset: changed _iterator() method on addset to work with a given order If the two collections are in ascending order, yield their values in an ordered way by iterating both at the same time and picking the values to yield.

revset: changed _iterator() in addset to use the generated list when available Now when all the elements have been generated, the iterator will just use the generated list instead of going through all the elements again.

revset: added cached generated list to addset This way when all the values have been generated the list can be sorted without having to generate them all again.

revset: changed sort method to use native sort implementation of smartsets When sort is done by revision or reversed revision number it can just call sort on the set and doesn't have to iterate it all over again.

revset: fixed sorting issue with spanset When a spanset was being sorted it didn't take into account it's current state (ascending or descending) and it reversed itself everytime the reverse parameter was True. This is not yet used but it will be as soon as the sort revset is changed to directly use the structures sort method.

tests: added tests to test sort revset This tests are intended to test sort in many different cases where it could fail when using the new structures

revset: added __nonzero__ method to spanset class Implemented it in a lazy way, just look for the first non-filtered revision and return True if there's any revision at all.