- Added exception points as a new class of "points" triggering on specific exception numbers, with a similar set of commands to breakpoints and registerpoints.
- Removed the per-instruction callback hook from device_debug. Only one driver was using this (rmnimbus.cpp), and what it was doing with it could be done more cleanly with exception points.
- Change the type of the action string parameter for "points"-creating methods and make some parameters optional for those.
- Change trace file logging to use a std::ostream instead of FILE * to take better advantage of strformat.
