Make save/restore default feature, the configure option for save/restore removed from configure script and save/restore made available forever. All code now assume it is exists. Bochs save/restore tree previosly called "save_restore" renamed to "bochs" tree and it will be havily used everywhere, starting from save/restore and ending by various bochs debugger functions. I am going to rework debugger code to get rid of debug CPU access functions and use this "bochs" param tree instead
* partial rewrite of the USB device emulation code (TODO: mouse and keypad)
* configure.in and iodev makefile updates
* removed old-style data structure for the USB harddisk
* TODO: save/restore support for removable devices
- PCI USB destructor now resets all runtime parameter handlers
- set log prefix for the SCSI device
- fixed a warning in the SCSI emulation code