New configuration header file to include/ exclude functionality.
Extracted privileged features from struct proc and create new struct priv.
Renamed various system calls for readability.
- current and maximum priority per process;
- quantum size and current ticks left per process;
- max number of full quantums in a row allow
(otherwise current priority is decremented)
The TTY driver now only notifies the IS server about function key event,
but does not tell which keys are pressed. The IS servers queries the TTY
driver to find out about this.
