It was impossible to create some table names on Windows
(e.g. LPT1, AUX, COM1, etc).

Fixed to pad dangerous names with thee "at" signs
(e.g. LPT1@@@, AUX@@@, COM1@@@, and so on).


include/my_sys.h:
  Adding new function declaration
mysys/my_access.c:
  Adding new function check_if_legal_tablename().
  It works almost like check_if_legal_filename(),
  but accepts a table name without extension and path,
  and does not check "CLOCK$".
sql/sql_table.cc:
  Check if a dangerous table name and append @@@
strings/ctype-utf8.c:
  Treat "@@@" sequence in a table name as a end-of-line.
mysql-test/r/ctype_filename.result:
  New BitKeeper file ``mysql-test/r/ctype_filename.result''
mysql-test/t/ctype_filename.test:
  New BitKeeper file ``mysql-test/t/ctype_filename.test''