Fixes bug 9090; bug not in any released Tor.

Spotted by Coverity Scan. Not in any released Tor.

Conflicts:
	src/or/config.c
	src/or/relay.c

This implements "algorithm 1" from my discussion of bug #9072: on OOM,
find the circuits with the longest queues, and kill them.  It's also a
fix for #9063 -- without the side-effects of bug #9072.

The memory bounds aren't perfect here, and you need to be sure to
allow some slack for the rest of Tor's usage.

This isn't a perfect fix; the rest of the solutions I describe on
codeable.

In my #7912 fix, there wasn't any code to remove entries from the
(channel, circuit ID)->circuit map corresponding to queued but un-sent
DESTROYs.

Spotted by skruffy. Fixes bug 9082; bug not in any released Tor.

Fixes bug 9002; bugfix on 0.1.1.11-alpha (which introduced guard
nodes), or on 0.0.6pre1 (which introduced hidden services).

dana koch authored 11 years ago and Nick Mathewson committed 11 years ago

This lets us have the possibility of fine-tuning the check in the tor_sscanf test cases at a later date.

Conflicts:
	src/or/relay.c

Using "ours" strategy to avoid taking commits

Using "ours" strategy to avoid taking changes.

This fixes bug 9047 (and some parts of 9031, 8922, 8883 that weren't
fixed in 8822).  Bugfix on 0.2.2.6-alpha.

I'm calling it a bugfix on 0.2.0.1-alpha, since that's where cell
queues were first introduced.