implement msc device class

usbd auto stall control for not supported return from class control request
usbd implement xfer isr callback mechanism
DCD
- implement dcd multiple qtd support
- dcd dcd_pipe_stall
- implement dcd_pipe_queue_xfer
- xfer_complete_isr
- flush control endpoint if received new setup while previous transfer is not complete
change msc_cmd_block_wrapper_t flags field to dir
force full speed for easy testing

NOTEs: somehow unable to get endpoint IN interrupt with ioc

demos/device/keyboard/mscd_app.h

@@ -0,0 +1,66 @@
+/**************************************************************************/
+/*!
+    @file     mscd_app.h
+    @author   hathach (tinyusb.org)
+
+    @section LICENSE
+
+    Software License Agreement (BSD License)
+
+    Copyright (c) 2013, hathach (tinyusb.org)
+    All rights reserved.
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions are met:
+    1. Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in the
+    documentation and/or other materials provided with the distribution.
+    3. Neither the name of the copyright holders nor the
+    names of its contributors may be used to endorse or promote products
+    derived from this software without specific prior written permission.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
+    EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+    WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
+    DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+    (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+    ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+    This file is part of the tinyusb stack.
+*/
+/**************************************************************************/
+
+/** \ingroup TBD
+ *  \defgroup TBD
+ *  \brief TBD
+ *
+ *  @{
+ */
+
+#ifndef _TUSB_MSCD_APP_H_
+#define _TUSB_MSCD_APP_H_
+
+#include "boards/board.h"
+#include "tusb.h"
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+#if TUSB_CFG_DEVICE_MSC
+
+#endif
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif /* _TUSB_MSCD_APP_H_ */
+
+/** @} */