Speed up tor bootstrap phase (chutney portion)

Speed up the tor bootstrap by modifying both tor and chutney.

Comprehensive bootstrap: (30s)
  Reduce the consensus interval to 10 seconds
   Depends on corresponding tor changes
  Don't require any bandwith for an exit flag
   Depends on corresponding tor changes

Fast Bootstrap: (10s)
  Assume that everything is reachable and an exit
  Start building paths once the minimum number of descriptors are available
  Reduce consensus validity to 2 intervals

Also make other minor config fixes

Resolves bug 13823. Tests resolution of (tor) bug 13718 and children.
Simplify some bits of logic
Group global imports at the top
Simplify more code by restructuring a bit
Add initial support for Python 3 alongside 2
Fix the last few pep8 warnings
Add HS torrc template and network configuration

This adds a network with an HS service bound to port 6000 that serves
port 22 on your local machine.

The hidden service is node test025h and the hostname can be found in
"$dir/hidden_service/hostname".

To start the network, use the "hs" network.

Fixes #13934

Signed-off-by: David Goulet <dgoulet@ev0ke.net>
Merge remote-tracking branch 'mvdan/master'
Merge branch 'master' of https://git.torproject.org/chutney into bug13823-fast-bootstrap
Fix Python 2 issues with refactoring

Fix missing brackets around print statements

Fix open on already open file.
Automatically create hidden service directory for hidden services

Add a new env hs (boolean) that is set to 1 for hidden services.

Add a new env hs_directory (string) that is set to the name of the hidden
service directory ('hidden_service' by default).

When hs is 1, create hs_directory with mode 0700 (448 decimal).
Merge branch 'bug13823-fast-bootstrap'
Merge branch 'bug13935-create-hs-directory'