USB redirection update

I've pushed an updated version of my usb-redirection code to my git repo. The biggest change is that the usbredir device now is a chardev frontend. Which means that the way to use it has changed. Also there now is proper emulation of companion controllers for the ehci code. Here is an example cmdline for using both:

-device usb-ehci,addr=0b.2,multifunction=on,id=ehci0 -device piix3-usb-uhci,addr=0b.0,multifunction=on,masterbus=ehci0.0,firstport=0
-device piix3-usb-uhci,addr=0b.1,multifunction=on,masterbus=ehci0.0,firstport=2
-chardev socket,id=usbredirchardev,host=localhost,port=4000
-device usb-redir,chardev=usbredirchardev,id=usbredirdev

There have also been some usbredir protocol changes, so you need to update and rebuild your usbredir clone too. I hope to release a usbredir-0.1.0 with a frozen protocol soon.