For the nat we will have NAT and MGCP in the same process
and this commit starts with that. We are linking in the MGCP
code and one can embed MGCP config snippets...
* Create struct bsc_nat and move the various lists into this structure
* Create the VTY code
* Call the VTY init and parsing code
* Create functions to create the types..
* Add some stuff into the bsc_connection to be used for the NAT with
proper config files. E.g. to close the connection if the BSC does not
respond to a given command.