[PATCH] Implement TP-VPF-ENHANCED

Hello :) Now I've implemented the TP-VPF-ENHANCED. To achieve that I added some goto-stuff - i hope that's ok. I think it makes sense here. It's again untested, but compiles fine. I'm working at the moment on a way to test SMS-PDU decoding. If that's easier you can simply merge the branch tp-vp from git://github.com/stefreak/openbsc.git :) The patch is attached. Greetings, Steffen