Enusure that my_global.h is included first

- Added sql/mariadb.h file that should be included first by files in sql
  directory, if sql_plugin.h is not used (sql_plugin.h adds SHOW variables
  that must be done before my_global.h is included)
- Removed a lot of include my_global.h from include files
- Removed include's of some files that my_global.h automatically includes
- Removed duplicated include's of my_sys.h
- Replaced include my_config.h with my_global.h

plugin/auth_gssapi/client_plugin.cc

@@ -31,13 +31,12 @@ POSSIBILITY OF SUCH DAMAGE.
 
   GSSAPI authentication plugin, client side
 */
-#include <string.h>
-#include <stdarg.h>
+#include <my_global.h>
 #include <mysqld_error.h>
 #include <mysql/client_plugin.h>
 #include <mysql.h>
-#include <stdio.h>
 #include "common.h"
+#include <string.h>
 
 extern int auth_client(char *principal_name,
                        char *mech,

plugin/auth_gssapi/gssapi_client.cc

@@ -26,9 +26,8 @@ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
 */
 
+#include <my_global.h>
 #include <gssapi/gssapi.h>
-#include <string.h>
-#include <stdio.h>
 #include <mysql/plugin_auth.h>
 #include <mysqld_error.h>
 #include <mysql.h>

plugin/auth_gssapi/gssapi_errmsg.cc

@@ -26,8 +26,10 @@ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
 */
 
+#include <my_global.h>
 #include <gssapi.h>
 #include <string.h>
+
 void gssapi_errmsg(OM_uint32 major, OM_uint32 minor, char *buf, size_t size)
 {
   OM_uint32 message_context;

plugin/auth_gssapi/gssapi_server.cc

@@ -1,6 +1,5 @@
-#include <my_config.h>
+#include <my_global.h>
 #include <gssapi/gssapi.h>
-#include <stdio.h>
 #include <mysql/plugin_auth.h>
 #include <my_sys.h>
 #include <mysqld_error.h>

plugin/auth_gssapi/server_plugin.cc

@@ -31,6 +31,7 @@
 
   GSSAPI authentication plugin, server side
 */
+#include <my_global.h>
 #include <my_sys.h>
 #include <mysqld_error.h>
 #include <mysql/plugin_auth.h>

plugin/auth_gssapi/sspi_client.cc

@@ -27,11 +27,10 @@ POSSIBILITY OF SUCH DAMAGE.
 */
 
 #define SECURITY_WIN32
+#include <my_global.h>
 #include <windows.h>
 #include <sspi.h>
 #include <SecExt.h>
-#include <stdarg.h>
-#include <stdio.h>
 
 #include <mysql/plugin_auth.h>
 #include <mysql.h>
@@ -180,4 +179,4 @@ cleanup:
     FreeCredentialsHandle(&cred);
   free(out);
   return ret;
-}
+}

plugin/auth_gssapi/sspi_errmsg.cc

@@ -26,8 +26,9 @@ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
 */
 
+#include <my_global.h>
 #include <windows.h>
-#include <stdio.h>
+#include <string.h>
 
 #define ERRSYM(x) {x, #x}
 static struct {

plugin/auth_gssapi/sspi_server.cc

@@ -26,6 +26,7 @@ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
 */
 
+#include <my_global.h>
 #include "sspi.h"
 #include "common.h"
 #include "server_plugin.h"