evolve: don't use python sets on top of revset for evolve --rev
In --rev we were wrapping the revsets in python sets.
This is wrong as the use python sets force the wrapper revision set to be
computed earlier than it has to and have no order guarantee.
Removing this wrapping changes a test because the ordering does not appear to
be the same but the end result is the same.
evolve: current bookmark wrongly moving during prune (issue4559)
Before this patch: prune -r <otherbookmark> also moved the current bookmark
eventhough it was not related to the pruned changes.
This patch fixes it and adds a test to catch regressions.