[USBOHCI]

[USBOHCI]
- Implement function to retrieve isochronous head endpoint descriptor
- Implement function to retrieve current frame number
- Set isochronous descriptor flag for head endpoint
- Implement retrieve device status for devices
- Implement retrieve class status from device
- Partly implement isochronous descriptor handling in usb queue
- Start implementing isochronous transfers in ISUBRequest
- Code currently not tested as the Virtual Machine with XP + ReactOS usbohci driver brings down the host system when starting the iso transfers. Ironically it crashes in MS usbohci driver

svn path=/branches/usb-bringup/; revision=51957