The timers now have a new member 'realtime' and they are driven by the
selected engine. The VGA update timer and the status LED timer now always use
the realtime mode, but the PIT and CMOS RTC depend on the clock options.
TODO: improve virtual timer to make operate in both modes at the same time.
The vga update code should always use the realtime mode and the pit timing
should depend on the clock option.
with the host time. After using a runtime config dialog or save and restore
simulation, this behaviour makes the PIT clock and the VGA update timer
running way too fast until it's back in sync. Now the elapsed time is stored
in the variable 'real_time_delay' and it is used to let the PIT clock run at
realtime speed, even if it is out of sync.
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
