Vanguards

- Workaround for dropped cell WARNS due to Tor bugs 29699, 29700,
29786, and 29927. These cases are now logged at INFO/NOTICE, with
specific Tor bug number for each case. 37
- Re-apply vanguard config params upon SIGHUP. 40.

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- Apply bandguards limits to non-HS circuits too. 34.

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- Global option to disable circuit killing. 32.
- Fix config parsing of boolean values. 36.
- Add tests/default.conf to sdist/pip tarball. 27
- Do not allow any dropped cells if Tor 0.3.4.10+ is being used. 25 and 3.
- Retry Tor connection if Tor is missing descriptors at startup. 35.
- Reorganized README_SECURITY to link to specific mitigation sections for each
adversary attack.

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- Fix exception when a connection to a guard is closed with more than one
live circuit. 29
- Catch control+c and exit cleanly. 30.
- Use Tor's network liveness events to double-check connectivity.
- Print out relevant versions at startup.

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- Read ExcludeNodes from Tor and don't pick layer2 or layer3 guards in this
set. 11
- Add --one_shot_vanguards and --disable_vanguards options (to enable
OnionBalance synchronization). 12
- Don't write to torrc by default. 18
- Keep attempting to reconnect if the control port dies. 19
- Support tighter bounds on dropped data to defend against DropMark,
and change circ_max_dropped_bytes_percent to circ_max_dropped_cells.
However, leave these at NOTICE pending Tor patch 25573. 20.
- Limit rend requests from relays that are not in our consensus. 22.
- Added connectivity accounting: WARN if we're disconnected or can't build
circuits for more than 'conn_max_disconnected_secs' and
'circ_max_disconnected_secs'. Also emit a NOTICE if a connection dies while
there are live circuits on it. 23
- Fix several false positive cases in rendguard. More may remain, so demote
logline to NOTICE for now. 24
- Change rendguard params to lower the false positive rate. If you use a
conf file, be sure to update the values there, if specified. 24.
- Standardize using WARN for messages that we're confident represent
serious issues, and use NOTICE for heuristics that may need more tuning.

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- Initial release