Add navqueue_goto_fileloc()
Add support for extended-style error regex patterns

... in filetypes_parse_error_message().
Add msgwin_parse_compiler_error()

... and get rid of msgwin_parse_compiler_error_line().
Modify msgwin_goto_compiler_file_line() to use the parsed fileloc object
Accommodate process_build_output_line() to new error parsing functions
Update documentation for error_regex
Use error_regex for builtin filetypes