Bug#17498 failed to put data file in custom directory use "data directory" option

- Using DATA/INDEX DIRECTORY option on Windows put data/index file into
  default directory because the OS doesn't support readlink().
- The procedure for changing data/index file directory is 
  different under Windows.
- With this fix we report a warning if DATA/INDEX option is used,
  but OS doesn't support readlink().


mysql-test/r/windows.result:
  - updated result file.
mysql-test/t/windows.test:
  - Added test case to verify we get warnings if we specify DATA/INDEX
    DIRECTORY on a platform which doesn't support readlink().
sql/sql_parse.cc:
  - Added warnings if DATA/INDEX DIRECTORY option is used but not supported
    by the target platform.

mysql-test/t/windows.test

@@ -17,4 +17,13 @@ use prn;
 create table nu (a int);
 drop table nu;
 
+#
+# Bug17489: ailed to put data file in custom directory use "data directory" option
+#
+--disable_warnings
+drop table if exists t1;
+--enable_warnings
+CREATE TABLE t1 ( `ID` int(6) ) data directory 'c:/tmp/' index directory 'c:/tmp/' engine=MyISAM;
+drop table t1;
+
 # End of 4.1 tests