Allow to process multiple repos in command server mode
Created originally on Bitbucket by Alexandr Altinchurin (Александр Алтынчурин)
Now the command server mode is able to work with a single repository. To switch to another repository, one needs to close command server and start another instance of Mercurial. If there were a possibility to select another repo in command server mode, it would reduce the overhead of starting Mercurial while processing a multiple repositories.