util: implement pop() on lrucachedict This moves __delitem__() to pop() as the requirement is pretty much the same, and reimplement __delitem__() by using pop().

util: add method to peek item in lrucachedict I want a function that doesn't unnecessarily update the internal state of the cache dict after fork().

commandserver: loop over selector events An IPC socket will be waited by the same selector.

commandserver: remove redundant "if True" block

commandserver: extract handler of new socket connection This prepares for adding an IPC socket.

commandserver: pass around option to hook repo instance creation This is necessary to wrap a repo instance so the master process will be notified on repo.close().