Add number_ios= option

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/server.h b/server.h
index 2f41be0..aefd418 100644
--- a/server.h
+++ b/server.h
@@ -38,7 +38,7 @@
 };
 
 enum {
-	FIO_SERVER_VER			= 24,
+	FIO_SERVER_VER			= 25,
 
 	FIO_SERVER_MAX_FRAGMENT_PDU	= 1024,