- applied parts of the new USB patch by Ben Lunt
- removed max_packet_size member from USB device structure
- usb_uhci: improved speed info
- updated USB-related documentation
- TODO: review and test the main part of the xHCI changes by Ben


git-svn-id: svn://svn.code.sf.net/p/bochs/code/trunk@12488 6c8e4198-a580-4521-a02f-c9ae86df1db9