o Minor bug fixes (torrc exit policies):
    - accept6/reject6 * lines only produce IPv6 wildcard addresses,
      previously they would produce both IPv4 and IPv6 wildcard addresses.
    - 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.
      * any ExitPolicy lines occur after accept/reject *:* or variants.
        These are redundant, and were always ignored.
    - 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.
      Resolves ticket 16069. Patch by "teor".
      Patch on 2eb7eafc9d78 and a96c0affcb4c (25 Oct 2012),
      released in 0.2.4.7-alpha.