* Full unprivileged instruction set support.
* On cache also allow calculate what time it would take with stalls.
* Unit tests for hazard unit
* Consider to notify MemoryView and ProgramView about changed range
  to limit update and redraw to required region only.
* Use background color to mark program and data in cache
* There seems to be some problem with layout recalculation when dock is
  pulled out of main window. When it's resized then it's immediately
  correctly recalculated.
* Implement and test more SPIM compatible syscalls.