Program configuration:
 - Add RTR server parameters.
 - Streamline header file headers.
CLI:
 - Add cli.h with parse_cli() declaration
 - Stramline header headers
 - Add RTR server CLI arguments to arg parser
RTR Integration:
 - Add rtr.h and rtr.c for RTR server connection.
 - Streamline header headers
BIRD RTRLIB CLI
 - Remove util.c and integrate in bird-rtrlib-cli.c
 - Update CMakeLists.txt for RTRLib integration.
 - Functioning RTR server connection with dumping callback and simple "exit" command for application
termination.