This commit fixes the following:
* #303 Endpoint 0 size is set according to device descriptor
* #302 Endpoint 0 callbacks will be re-configured after every usb-set-configuration
* #302 usb-set-configuration bogus value check
* #302 Alternate setting configuration reset after every usb-set-configuration
* usb_f103 pma_top should not include ep0 size