The code that detected the source of a remapped address checked that
an address mapping's source was a given rewrite rule if addr_orig had
no .exit, and addr did have a .exit after processing that rule.  But
addr_orig was formatted for logging: it was not the original address
at all, but rather was the address escaped for logging and possibly
replaced with "[scrubbed]".

This new logic will correctly set ADDRMAPSRC_NONE in the case when the
address starts life as a .exit address, so that AllowDotExit can work
again.

Fixes bug 6211; bugfix on 0.2.3.17-beta

It turns out this can happen.  Even though there is no reason for
connections to be marked but reading, we leave them reading anyway,
so warning here is unwarranted.  Let's turn that back on once we do
something sensible and disable reading when we mark.  Bugfix for
6203 on Tor 0.2.3.17-beta.

Thanks to cypherpunks for pointing out the general stupidity of the
original code here.

Bug 4748

squash! Document 0.2.3.x torrc/default-torrc/command line semantics changes

Incorporates fixes suggested by rransom.

On some platforms, the linker is perfectly happy to produce binaries
that won't run if you give it the wrong set of flags.  So when not
cross-compiling, try to link-and-run a little test program, rather
than just linking it.

Possible fix for 6173.

Fix for bug 3311.

Previously, a directory would check the latest NS consensus for
having the signatures the client wanted, and use that consensus's
valid_until time to set the HTTP lifetime.  With this patch, the
directory looks at NS consensus or the microdesc consensus,
depending on what the client asked for.

I don't believe this bug occurs, but there was an XXX023 to make
sure it doesn't.

Previously it duplicated some getrlimit code and content from compat.c;
now it doesn't.