Discard circuit paths on which nobody supports ntor

Right now this accounts for about 1% of circuits over all, but if you
pick a guard that's running 0.2.3, it will be about 6% of the circuits
running through that guard.

Making sure that every circuit has at least one ntor link means that
we're getting plausibly good forward secrecy on every circuit.

This implements ticket 9777,
Update to the February 2014 GeoIP database.
Call ENETUNREACH a case of NOROUTE, not a case of INTERNAL.

Found by cypherpunks; fix for a part of bug 10777; bugfix on 0.1.0.1-rc.
Don't treat END_STREAM_REASON_INTERNAL as total circuit failure

It can happen because we sent something that got an ENETUNREACH
response.

Bugfix on 0.2.4.8-alpha; fixes a part of bug 10777.
Excise the insertion_time_elem_t logic

It's now redundant with the inserted_time field in packed_cell_t

Fixes bug 10870.
make EACCES survivable too.
Merge remote-tracking branch 'public/bug10777_nointernal_024' into maint-0.2.4
update changes file
Merge branch 'bug10777_netunreach_024' into maint-0.2.4
Fix windows compilation of e0c8031516852

There is no WSAEPERM; we were implying that there was.This fixes a
bug in e0c8031516852143fb82d8fee91a0f4c576c7418, which hadn't yet
appeared in any released Tor.
Update geoip6 to the February 2014 GeoIP database.
gcc/clang: Mark macro-generated functions as possible unused

clang 3.4 introduced a new by-default warning about unused static
functions, which we triggered heavily for the hashtable and map function
generating macros. We can use __attribute__ ((unused)) (thanks nickm for
the suggestion :-) ) to silence these warnings.
changes file for bug 10904
Merge remote-tracking branch 'karsten/geoip-feb2014' into maint-0.2.3
Merge remote-tracking branch 'origin/maint-0.2.3' into maint-0.2.4
Merge remote-tracking branch 'karsten/geoip6-feb2014' into maint-0.2.4
Enveigle configure to look for a2x.py as well as a2x.

It's not guaranteed that every package symlinks a2x to a2x.py; OpenBSD
does not do this, so let's just look for a2x.py as well.
add changes file for bug 10929
whoops; mistaek in a496010642c2. so many comma
Merge remote-tracking branch 'public/feature9777_024_squashed' into maint-0.2.4