When passing multiple subnet files, e.g., by using -s/--subnets
multiple times or by using it together with subnets passed as positional
arguments append the content from all sources instead of only using the
subnets from the last source. This makes the behaviour of -s/--subnets
consistent with -x/--exclude.

As @brianmay observed in #82 this option is no longer used and can be
dropped.

Fixes the kind of problems reported on #75 but does break the command
line "API" (hopefully).

This allows disabling all client tests using a conftest.py file, if for
example #56 gets merged and the server supports more python versions
then the server.

The server side tests are very incomplete.

Due to nested shells, we need to have multiple layers of quoting. Yuck.

Closes #80

In situations where 2.7 is available and some unsupported 3.x is the
system's default we should probably fallback to 2.7 instead of the
default (that might be e.g. 3.4). This might fix #78.

The fish shell doesn’t support ‘||’ and requires a ‘—python python’
workaround.  This change explicitly calls /bin/sh for the remote shell
commands.

Just because we may have found IPv6 DNS servers from /etc/resolv.conf
doesn't mean we should force IPv6 support.

Instead we should disable the IPv6 DNS servers if IPv6 is disabled.

Note: this will also result in any IPv6 servers specified on the command
line being silently ignored too.

Specifying an IPv6 subnet will still require IPv6 support.

Closes #74

Closes #73.

In some cases (see #43) it seems that some network configurations may
end up setting a skip on lo. As sshuttle adds rules that rely on
filtering/translating packets on lo, this causes problem. This fix
overrides the skip and makes the rules be applied again.
Should fix at least some of the problems reported on #43.

This will make it easier to support other platforms/versions in the
future, e.g., OpenBSD.

This is the error message that this commit fixes:
TypeError: sequence item 142: expected a bytes-like object, str found

Complete what 1c46f25e started, more or less.

Closes: #68

Wew were trying to allocate an IPv6 socket even though we weren't using
IPv6, causing failures on systems without IPv6 support available.

This change means a number of methods on MultiListener, e.g. setsockopt,
should not be called until after the bind call.

Closes #68

Closes: #65

And some subtle grammar.

Closes: #66

Copied from https://coderwall.com/p/adfxgw/sshuttle-on-windows

Closes #64

It is autogenerated.

Closes #60.

Suspect it is causing sphinx to crash on readthedocs. See
https://github.com/sphinx-doc/sphinx/issues/1871

Not required as we are not documenting the source code.