Add an option that makes Tor use fewer connections
Tor is willing all the file descriptors the OS tells it are available for the current user. So to enforce a connection limit, operators need to drop the user file descriptor limit. But if the OS is wrong, or there are multiple tor instances under the user, tor can easily exceed this limit. Or machine hits a kernel, RAM, or CPU limit first, then the user might want to artificially limit connections.
Right now, we have ConnLimit, which looks like it limits connections, but it's actually a minimum. And we have the out of socket check, but DisableOOSCheck is the default.
Does enforcing a connection limit require us to set DisableOOSCheck 0? Then we should move this ticket to 0.3.4, and open one to improve the out of socket check.