Update core headers and sources to use relative includes

src/core/os/mem/mem_os.h

@@ -1,8 +1,8 @@
 #ifndef MEM_OS_H
 #define MEM_OS_H
 
-#include "aliases.h"
-#include "platform.h"
+#include "../../../common/aliases/aliases.h"
+#include "../../../common/platform/platform.h"
 
 #ifdef __cplusplus
 BEGIN_C_LINKAGE
@@ -11,9 +11,9 @@ BEGIN_C_LINKAGE
 #include "mem_os_ops.h"
 
 #if defined(WAPP_PLATFORM_WINDOWS)
-#include "mem_os_win.h"
+#include "win/mem_os_win.h"
 #elif defined(WAPP_PLATFORM_POSIX)
-#include "mem_os_posix.h"
+#include "posix/mem_os_posix.h"
 #else
 #error "Unrecognised platform"
 #endif