Bristuff HFC support ported to CallWeaver

I just ported the HFC parts from Bristuff (see http://www.junghanns.net/ for more info) to CallWeaver. There are works in progress to make ISDN support in Unicall, but I had no time to wait, so I ported Junghanns’ old code. The code isn’t likely to be part of the release since it breaks compiling zaptel without being bristuffed, but if you’re at it, please test it. You can find it in my branch: http://svn.callweaver.org/callweaver/branches/royk/bristuffed/