Cope with comment lines that extend beyond 120 characters.  Otherwise xl2tpd
will try to interpret the 120th character of the line as the start of the
next line, which will usually end in a cryptic error message.  See also
Fedora BZ#806963.
Increase the size of the buffer used to read config file lines.

The config file format treats any character after a semicolon as a comment,
so that people can comment config after the line.  The current line limit
of 120 characters is easy enough to overflow with this sort of (sane)
documentation style; let's increase it to 1024 bytes.  Patch from Fedora's
bz#806963.
Don't call grantpt().

Use of grantpt() is fraught: we run with a SIGCHLD handler, which
can lead to undefined results on systems that exec a setuid child
process to fiddle the ownership/permissions of the slave pty when a
child pppd process dies at just the right moment.  In addition, it
reportedly interacts badly with SELinux.

It turns out that there's no need to call grantpt() anyway.  Child pppd
processes run as root and so should be able to access the slave ptys with
their original ownership and permissions.  On FreeBSD/Mac OS X, grantpt()
doesn't actually do anything interesting and has been presumably been
working fine.  Fedora has been shipping with a patch to disable the call
to grantpt, and OpenBSD is completely unaffected, so this looks pretty
safe.
Merge commit 'fff70' into testing
Merge commit '67bfe' into testing
Merge commit 'c52b' into testing