Make it possible to disable dormant mode altogether

There is currently no configuration option to disable tor's dormant mode. One can prevent it indirectly by 1) occasionally sending traffic over the SOCKS port, 2) telling tor to set up an onion service, or by 3) sending tor a SIGNAL ACTIVE (but that only wakes up tor when it's sent from a control port connection that was established after tor went dormant).

In the context of bridgestrap, it would be convenient to simply disable dormant mode rather than deal with the above workarounds. Bridgestrap tests bridges by sending a SETCONF [bridge] to tor's control port; it never performs any client activity.

TL;DR: I'd like to have a configuration option that tells tor to never go dormant.