Improved debug lexer and parser output.

Renamed monitor_debug_print_parse_tree() to
monitor_debug_verbose_print_parse_tree().

Replaced monitor_debug_added_to_parse_node() and
monitor_debug_found_parse_node() functions with similar
monitor_debug_scanned_terminal(), monitor_debug_parsed_non_terminal()
and monitor_debug_parsed_non_terminal_list() functions.

Changed debug output to show the full description for terminal nodes but
the applicable parser rule for terminals.