Make gcc happy and remove a couple of warnings

Remove the callbacks from gsm_network for now. A set of different
callbacks will be back. E.g. when the paging is completed, when the
Q.931 like call handling is there...

Remove var's or move them into #if 0, remove unused stuff that looks
like we do not need it anytime soon or #if 0 them, move stuff around.
tree: 5562f8e489233fc4d95776920a1ab3c80b7dacf2
  1. tests/
  2. tools/
  3. AUTHORS
  4. configure.in
  5. COPYING
  6. Makefile.am
  7. README