Changes:
* Remove interface name argument from patty_ax25_if_new()
* Add interface name argument to patty_ax25_server_if_add()
* Add interface name argument to patty_daemon_if_add()
* In src/server.c, implement 'struct if_entry' to hold the interface
name, file descriptor, and pointer to a patty_ax25_if object, to
recouple names to their respective interfaces
* Add a return argument to patty_bin_if_create() to store a pointer
to a new interface name created from a declaration