- complete implementation of option 'n' in lang_conf.
- add one more check: repeated arguments in inout/out part of procedure call.
- explain better the error message of repeated variable in procedure call.
- improve main.cpp: now accepts arguments.
- replace tabs with 4 spaces and remove trailing spaces
- add option to main.cpp: -q: be quiet: do not print errors.
- set default procedure name to call: main.