2. Fix data transfer size calculate error issue;

[USB]fix rt_usbd_set_config() BUG which set the USB device to configuration state before enumerating the device.

2.adjust some viable and micro name
3.some other small fix

Pass USB CV test verification;
Code cleanup;

RT_RINGBUFFER_SIZE could mean "the size of the whole buffer", "the size
of the empty space" or "the size of the data". Moreover, it's never a
micro anymore. Change it to rt_ringbuffer_data_len before it's too late.
Also, RT_RINGBUFFER_EMPTY is changed to rt_ringbuffer_space_len.

Some driver will emit USB_MSG_DATA_NOTIFY before the USB get configured.
Filter out those events.

When the core received an USB_MSG_PLUG_OUT event, it will stop all the
classes. This make a chance that the classes could get rid off doing
useless stuff while the USB cable is plugged out.

When the USB got RESET packet from the host and the address is setup,
all the classes will got reset. The reset is done by class stop and than
class run. So the classes should reset their internal state in
class_{run,stop}.

Besides, the USB device driver could post a USB_MSG_RESET message on
every RESET packet.

Reset the vcom state in class_{run,stop} and when the PC is not
receiving data from me.

Although currently the only message send to the queue is struct
udev_msg, in order to keep backward compacity and for extention in the
future, we set the size of message to 32.

It also add two configurations for the USB device even loop thread:

    RT_USBD_THREAD_STACK_SZ to set the stack size, default to 2048
    RT_USBD_THREAD_PRIO     to set the priority, default to 8

You can overwrite the default values in rtconfig.h

We start the sending transaction in SOF handler. But if the data is
already sending, start an other transaction will cause data lose.
Implement a state machine is cdc_vcom and avoid that.

Sort the switch cases by the frequency of the events.

The data filled into dcd_ep_write does not to be limited by
MaxPacketSize.

This commit set the buffer for packet to CDC_MaxPacketSize which is a
reasonable value for it. However, maybe we should make
CDC_{RX,TX}_BUFSIZE configurable as well.

This could crash the program with -O1 and -O2 in MDK.

remove product ID

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2580 bbd45198-f89e-11dd-88c7-29a3b14d5316

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2579 bbd45198-f89e-11dd-88c7-29a3b14d5316