This is a big-ish patch, but it's very straightforward. Under this
clang warning, we're not actually allowed to have a global variable
without a previous extern declaration for it. The cases where we
violated this rule fall into three roughly equal groups:
* Stuff that should have been static.
* Stuff that was global but where the extern was local to some
other C file.
* Stuff that was only global when built for the unit tests, that
needed a conditional extern in the headers.
The first two were IMO genuine problems; the last is a wart of how
we build tests.
When parsing torrc ExitPolicies, we now warn if:
* an IPv4 address is used on an accept6 or reject6 line. The line is
ignored, but the rest of the policy items in the list are used.
(accept/reject continue to allow both IPv4 and IPv6 addresses in torrcs.)
* a "private" address alias is used on an accept6 or reject6 line.
The line filters both IPv4 and IPv6 private addresses, disregarding
the 6 in accept6/reject6.
When parsing torrc ExitPolicies, we now issue an info-level message:
* when expanding an accept/reject * line to include both IPv4 and IPv6
wildcard addresses.
In each instance, usage advice is provided to avoid the message.
Partial fix for ticket 16069. Patch by "teor".
Patch on 2eb7eafc9d and a96c0affcb (25 Oct 2012),
released in 0.2.4.7-alpha.
