Correct a couple of header file issues in the base EightBit library

Signed-off-by: Adrian Conlon <Adrian.conlon@gmail.com>

inc/IntelProcessor.h

@@ -4,8 +4,12 @@
 #include <array>
 
 #include "Processor.h"
+#include "Register.h"
 
 namespace EightBit {
+
+	class Bus;
+
 	class IntelProcessor : public Processor
 	{
 	public:

inc/Memory.h

@@ -2,6 +2,7 @@
 
 #include <cstdint>
 #include <vector>
+#include <string>
 
 namespace EightBit {
 	class Memory {