client code added to the embedded library
some fixes


include/mysql.h:
  test code removed
  simple_command is the macrodefinition now
libmysqld/embedded_priv.h:
  this declaration obsolete
libmysqld/lib_sql.cc:
  errors stored in the same place for embedded and client libraries now
sql-common/client.c:
  we don't need that ugly wrapper