localrepo: introduce "prepushoutgoinghooks" to extend outgoing check easily This patch introduces "prepushoutgoinghooks" to extend outgoing check before pushing changesets to remote easily. This chooses the function returning "util.hooks" instead of the one to be overridden. The latter may cause problems silently, if one of overriders forgets (or fails) to execute a kind of "super(xxx, self).overridden(...)". In the other hand, the former can ensure that all registered functions are invoked, unless one of them raises an exception.