Clean up of debugging logs and new commands.

As this project grows it becomes important to keep things properly organised.
In this commit I've put some effort into making the kernel.cpp file more consise and thus improve its
readability.
Certain parts of the code have gotten their own definition file where before it
was only a header file.

- Moving the Supervisor Terminal into its own definition file.
- Subtracting debugging messages with preprocessor ifdef's
- Time and Date is now not just a header but has its own proper definition file
- Banner is displayed when booting up
- Terminal has a couple new commands

	Commmand		Description
	=================|||||===================================================
	DATE (was TIME)		Displays the curren time, date and ticks
	VERSION			Displays system version information
	MEMORY			Displays memory information

src/kernel/serial.h

@@ -4,7 +4,11 @@
 #include "io.h"
 #define PORT 0x3f8 
 static int init_serial() {
-   printf("Init serial\n");
+
+#ifdef __VERBOSE__
+   printf("Init Serial\n");
+#endif
+   
    outb(PORT + 1, 0x00);    // Disable all interrupts
    outb(PORT + 3, 0x80);    // Enable DLAB (set baud rate divisor)
    outb(PORT + 0, 0x03);    // Set divisor to 3 (lo byte) 38400 baud