count DATA cells with stream ID 0 as delivered for SENDME purposes

Found while investigating 8093, but probably not the cause of it,
since this bug would result in us sending too few SENDMEs, not in us
receiving SENDMEs unexpectedly.

Bugfix on the fix for 7889, which has appeared in 0.2.4.10-alpha, but
not yet in any released 0.2.3.x version.
Check spawn_func() return value

If we don't, we can wind up with a wedged cpuworker, and write to it
for ages and ages.

Found by skruffy.  This was a bug in 2dda97e8fd898757, a.k.a. svn
revision 402. It's been there since we have been using cpuworkers.
More hacking around spawn_func issues

This time, we use a pthread_attr to make sure that if pthread_create
succeeds, the thread is successfully detached.

This probably isn't the big thing going on with 4345, since it'd be
a bit weird for pthread_detach to be failing.  But it's worth
getting it right.
Remove TunnelDirConns and PreferTunnelledDirConns

These options were added back in 0.1.2.5-alpha, but no longer make any
sense now that all directories support tunneled connections and
BEGIN_DIR cells.  These options were on by default; now they are
always-on.

This is a fix for 10849, where TunnelDirConns 0 would break hidden
services -- and that bug arrived, I think, in 0.2.0.10-alpha.
Give specific warnings when client-side onionskin handshakes fail

Fix for bug9635.
Better log message when writing a CR in text mode on windows

Help to diagnose #11233
Forbid TunneledDirConns 0 and PreferTunneledDirConns 0 if being a HS

Fixes bug 10849; bugfix on 0.2.1.1-alpha (I believe)
Fix memory leaks in test_circuit_timeout

Found with valgrind.
Fix memory leak in test_onion_queues
Fix memory leak in test_geoip
fix uninitialized memory reads from test_geoip_with_pt. Found with valgrind
Fix memory leaks in test_cntev_append_cell_stats
Fix memory leak in test_util_asprintf
Fix memory leak in unittest helper function.
Fix a leak in test_buffer_allocation_tracking
Memory leaks in test_config_addressmap
Fix leaks in test_exit_policy_dump_to_string
test_cntev_append_cell_stats now no longer leaks
Fix numerous leaks in test_pt.c

I didn't find a managed_proxy_free() function any place; shouldn't
there be one?
Fix leaks in test_dir_formats