Fix #18240.  This version of the bug first appeared in
0.2.8.2-alpha.  0.2.8.1-alpha and earlier had a different bug.

Based on a patch from cypherpunks.

Yawning Angel authored 8 years ago and Nick Mathewson committed 8 years ago

Detect newer versions and fix our TLS code to use the new API.

Yawning Angel authored 8 years ago and Nick Mathewson committed 8 years ago

It appears that setting the various callbacks is no longer required, so
don't.

Found with my wacky symbol-usage-enforcer.

Patch from icanhasaccount; closes 18462.

Fixes the last case of 17744.

Only when we were actually flushing the cell stats to a controller
would we free them.  Thus, they could stay in RAM even after the
circuit was freed (eg if we didn't have any controllers).

Fixes bug 18673; bugfix on 0.2.5.1-alpha.