Fix authorized_client implementation a bit more

We previously added a fix for CVE-2013-6410, but that one accidentally
broke checks for non-netmasked entries entirely, rather than limiting it
to what it was actually supposed to allow. '\n' is also a character...

This fixes it properly, by not relying on string functions anymore, but
instead parsing all IP addresses to their binary representation, and
comparing that.

As an added bonus, we now also support IPv6 addresses in the ACL file.
Unbreak virtstyle parameter parsing

There have been issues with the "cidrhash" option of the "virtstyle"
parameter since a long time, in that the way things were being parsed
wasn't very endian-independent.

Fix it the same way we just fixed the authorized_client function.