On some profiles of Andrea's from #11332, I found that a great deal
of time can still be attributed to functions called from
update_router_have_minimum_dir_info().  This is making our
digestmap, tor_memeq, and siphash functions take a much bigger
portion of runtime than they really should.

If we're calling update_router_have_minimum_dir_info() too often,
that's because we're calling router_dir_info_changed() too often.
And it looks like most of the callers of router_dir_info_changed()
are coming as tail-calls from router_set_status() as invoked by
channel_do_open_actions().

But we don't need to call router_dir_info_changed() so much!  (I'm
not quite sure we need to call it from here at all, but...) Surely
we don't need to call it from router_set_status when the router's
status has not actually changed.

This patch makes us call router_dir_info_changed() from
router_set_status only when we are changing the router's status.

Fix for bug 12170.  This is leftover from our fix back in 273ee3e8
in 0.1.2.1-alpha, where we started caching the value of
update_router_have_minimum_dir_info().

(See discussion on #9553)

Conflicts:
	src/or/microdesc.c

The 0.2.5.x warning is the one that might help us track this down; the
warnings in stable are just annoying users over and over and over.

on #9686, gmorehose reports that the 500 MB lower limit is too high
for raspberry pi users.

This is a backport of 64724872 to 0.2.4.

Note that in 0.2.4, the option is called MaxMemInCellQueues.

When clearing a list of tokens, it's important to do token_clear()
on them first, or else any keys they contain will leak.  This didn't
leak memory on any of the successful microdescriptor parsing paths,
but it does leak on some failing paths when the failure happens
during tokenization.

Fixes bug 11618; bugfix on 0.2.2.6-alpha.

Fixes bug 10849; bugfix on 0.2.1.1-alpha (I believe)

Fixes the surface behavior of #11553

The server cipher list is (thanks to #11513) chosen systematically to
put the best choices for Tor first.  The client cipher list is chosen
to resemble a browser.  So let's set SSL_OP_CIPHER_SERVER_PREFERENCE
to have the servers pick according to their own preference order.

Now it only has dannenberg

Conflicts:
	src/or/circuituse.c

Fixes bug 11519, apparently bugfix on 0.2.3.11-alpha.

Conflicts:
	src/or/routerlist.h

I used a list of certificate files from arma, and a little script,
both at 11464.

(I need a list of actual signing keys to blacklist.)

Back in 175b2678, we allowed servers to recognize clients who are
telling them the truth about their ciphersuites, and select the best
cipher from on that list. This implemented the server side of proposal
198.

In bugs 11492, 11498, and 11499, cypherpunks found a bunch of mistakes
and omissions and typos in the UNRESTRICTED_SERVER_CIPHER_LIST we had.
In #11513, I found a couple more.

Rather than try to hand-edit this list, I wrote a short python script
to generate our ciphersuite preferences from the openssl headers.

The new rules are:
  * Require forward secrecy.
  * Require RSA (since our servers only configure RSA keys)
  * Require AES or 3DES. (This means, reject RC4, DES, SEED, CAMELLIA,
    and NULL.)
  * No export ciphersuites.

Then:
  * Prefer AES to 3DES.
  * If both suites have the same cipher, prefer ECDHE to DHE.
  * If both suites have the same DHE group type, prefer GCM to CBC.
  * If both suites have the same cipher mode, prefer SHA384 to SHA256
    to SHA1.
  * If both suites have the same digest, prefer AES256 to AES128.

The major changes are to re-order some ciphers, to drop the ECDH suites
(note: *not* ECDHE: ECDHE is still there), to kill off some made-up
stuff (like the SSL_RSA_FIPS_WITH_3DES_EDE_CBC_SHA suite), to drop
some of the DSS suites... *and* to enable the ECDHE+GCM ciphersuites.

This change is autogenerated by get_mozilla_ciphers.py from
Firefox 28 and OpenSSL 1.0.1g.

Resolves ticket 11438.

Fixes bug 11437; bugfix on 0.2.4.7-alpha.

Found by coverity; this is CID 1198198.

We are searching @CONFDIR@ before $HOME, but the documentation
implied otherwise.

I screwed this up in f5e86bcd, when I
first documented the $HOME/.torrc possibility.

Fix for bug 9213; bugfix on 0.2.3.18-rc.

This is a fix for 9700, which we already fixed in 0.2.5.x, but which
got left in 0.2.4.x.

This is a partial backport of a0a855d5

When I removed some unused functions in 5bfa373e, this became
unused as well.

This prevents long stalls when we're starting with a state file but
with no bridge descriptors.  Fixes bug 9229.  I believe this bug has
been present since 0.2.0.3-alpha.