Function CheckLanguage

Checks rules from the 'C++ language rules' section of cppguide.html. Some of these rules are hard to test (function overloading, using uint32 inappropriately), but we do the best we can. Args: filename: The name of the current file. clean_lines: A CleansedLines instance containing th

(filename, clean_lines, linenum, file_extension,
                  include_state, nesting_state, error)