allow varying number of message ports
grc: patches for 'allow varying number of message ports' (WIP)
grc: fixes undefined behavior in get_nports() (WIP)
grc: rewrite of nports code (WIP)
grc: make statement more explicit
grc: rename remove_duplicate -> remove_clone
grc: check if stream port before overwriting key and set _key, not 'key' in dict
grc: doc fixes
Merge remote-tracking branch 'skoslowski/grc_var_num_msg_ports'