revamp most comment handling * comment-list.h (octave_comment_elt::comment_type): New value, full_line. * lex.h (lexical_feedback::comment_text): New member variable. (lexical_feedback::finish_comment): New function. (octave_lexer::grab_block_comment, octave_lexer::grab_comment_block, octave_lexer::process_comment): Delete. * lex.ll (BLOCK_COMMENT_START, LINE_COMMENT_START): New exclusive start states. (ANY_INCLUDING_NL): New pattern. (<INPUT_FILE_START>{ANY_INCLUDING_NL}): Use it instead of ".". (^{S}*{CCHAR}\{{S}*{NL}, <BLOCK_COMMENT_START>^{S}*{CCHAR}\{{S}*{NL}, <BLOCK_COMMENT_START>^{S}*{CCHAR}\}{S}*{NL}, <BLOCK_COMMENT_START>.*{NL}, {S}*{CCHAR}.*{NL}, <LINE_COMMENT_START>{S}*{CCHAR}.*{NL}, <LINE_COMMENT_START>{ANY_INCLUDING_NL}): New patterns and rules for handling comments. ({CCHAR}, ^{S}*{CCHAR}\{{S}*{NL}): Delete old rules for comments. (display_start_state): Also handle BLOCK_COMMENT_START and LINE_COMMENT_START.