allow help for ordinary functions to work again (bug #65220) * comment-list.h (comment_elt::doc_string): Delete enum element. The lexer and parser no longer attempt to tag comments as doc strings when they are initially recognized so this tag is unused now. (comment_elt::is_doc_string): Delete function. (comment_list::find_doc_comment, comment_list::find_doc_string): New functions. * lex.h, lex.ll (lexical_feedback::m_classdef_doc_string, lexical_feedback::m_doc_string): Delete data members and all uses. (base_parser::finish_comment): Don't try to recognize doc string here. * parse.h, oct-parse.yy (classdef_beg): Don't try to recognize doc string here. (classdef): Use stash_comment to grab comment before END instead of calling lexer.get_comment inside rule. Don't try to recognize doc string here. * (base_parser::make_script): Examine comment lists attached to commands to find doc string. * (base_parser::make_function): Examine leading and body comment lists to find doc string. For classdef methods, attempt Matlab compatible behavior by looking at whether comments only use '%' characters. * (base_parser::start_function): New argument, doc_string. Use it instead of asking the lexer for the doc string. * (base_parser::make_classdef): New argument, bc. Delete it on error. Extract doc string from leading or body comment. * help.cc (help_system::raw_help_from_symbol_table): When searching using the full name and a class is found, only search for a constructor if the full name contains a '.' and there is no doc string for the class itself. If a class is found and there is no doc string for the class itself or a constructor, generate a simple doc string indicating that the class exists but is undocumented.