- added method to change port ownership.
- fixed UHCI reset and initialized device pointers.
- added symbol UHCI_FULL_DEBUG to reduce debug output if not set.
- renamed connection handling method.
emulation and usb_uhci.cc implements the setup for the PIIX3 chipset and the
runtime device change code. The UHCI core is required for the EHCI emulation,
since there can be multiple "companion" controllers for USB 1.1 device handling.