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)

Userland/strace.cpp

@@ -54,7 +54,7 @@ int main(int argc, char** argv)
     }
 
     for (;;) {
-        dword call[5];
+        u32 call[5];
         int nread = read(fd, &call, sizeof(call));
         if (nread == 0)
             break;