Does a lot of work towards the PIT

Added a math library, with clamp and POW.
added printf support for printing doubles
added a few helper functions in PIT for calcaulting the time in seconds of a clock cycle based on divisor

kernel/kmain.c

@@ -9,6 +9,7 @@
 #include <kernel/x86/io.h>
 #include <kernel/x86/keyb.h>
 
+#include <kernel/x86/pit.h>
 
 
 void kmain(void)
@@ -27,6 +28,8 @@ void kmain(void)
 	
 	init_kb();
 
+	printf("%f\n", get_time_from_divisor(10));
+
 	printf("Entering loop...\n");
 	while (1) {