main: add VTY and '-c config-file' option

Add config file, mainly for logging control.

Open VTY on the OMSO_VTY_PORT_HLR added to libosmocore in
commit 92fa18e6b800a27aa064a5fb8321cddd7383ae20
aka change-id I08cb52d9399a27e6876e45da36f434708c4fddef.

Add hlr_vty.h/c for standard VTY setup.
Add -c option to pass config file.
Add --version option.

Change-Id: Iedb884345a597371a337b0c67eb6013b7d5d1ce1
4 files changed