Added mysqltest for <=>
Removed use of TAB in output from mysql-test-run


Docs/manual.texi:
  Changelog
client/mysqltest.c:
  Added missing argument;  Changed to use standard defines
mysql-test/README:
  Cleaned up
mysql-test/mysql-test-run.sh:
  Removed use of TAB in output
  (We are now also depening on sed)
sql/item_cmpfunc.cc:
  Fixed <=>
sql/item_cmpfunc.h:
  Fixed <=>