AK: Rename the common integer typedefs to make it obvious what they are.

These types can be picked up by including <AK/Types.h>:

* u8, u16, u32, u64 (unsigned)
* i8, i16, i32, i64 (signed)

AK/ELF/ELFImage.cpp

@@ -1,7 +1,7 @@
 #include "ELFImage.h"
 #include <AK/kstdio.h>
 
-ELFImage::ELFImage(const byte* buffer)
+ELFImage::ELFImage(const u8* buffer)
     : m_buffer(buffer)
 {
     m_valid = parse();