- Add alias names for parameters:
     "node"   -> "mode"
     "dp"     -> "ton"
     "switch" -> "dialect"
     "l1"     -> "layer1"

  (Switching between ftmod_libpri and ftmod_isdn is easier now.)

- Removed unused members from struct ftdm_libpri_data
  and rename misnamed ones
Signed-off-by: Stefan Knoblich <s.knoblich@axsentis.de>