Project restructure (no new code added)

Moved all header files into include/ and removed their C counterparts -> code inside .h files
Also added a kernel.ld linker file
since we don't have many code files in src/ now, i removed src/kernel/
only real code change is that i moved memcopy() and memset() into string.h from system.h

include/stdint.h

@@ -0,0 +1,21 @@
+#ifndef STDINT_H
+#define STDINT_H
+
+#define NULL ((void*)0)
+
+// Signed ints
+typedef signed char int8_t;
+typedef signed short int16_t;
+typedef signed int int32_t;
+typedef signed long long int64_t;
+
+// Unsigned ints
+typedef unsigned char uint8_t;
+typedef unsigned short uint16_t;
+typedef unsigned int uint32_t;
+typedef unsigned long long uint64_t;
+
+// Other
+typedef unsigned int size_t;
+
+#endif