Initial commit of my USB test code which can exercise connected USB
devices and the FreeBSD USB stack itself. This program can be used to
test compliance against well established usb.org standards, also
called chapter-9 tests. The host platform can act as either USB device
or USB host depending on the available hardware. The basic USB
communication happens through FreeBSD's own libusb v2, and some
sysctls are also used to invoke specific error conditions. This test
program can be used to verify correct operation of external USB
harddisks under heavy load and various other conditions. The software
is driven via a simple command line interface. Main supported USB host
classes are "USB mass storage" and "USB modems".