Add clang-format file

Also run it across the whole tree to get everything using the One True Style.
We don't yet run this in an automated fashion as it's a little slow, but
there is a snippet to do so in makeall.sh.

Kernel/Scheduler.h

@@ -26,6 +26,7 @@ public:
     static Process* colonel();
     static bool is_active();
     static void beep();
+
 private:
     static void prepare_for_iret_to_new_process();
 };