General: Include headers directly where necessary

Ensures includes are explicitly included where necessary to avoid
indirect inclusions.

lib/DirectoryEnumerator.cpp

@@ -1,3 +1,5 @@
+#include "nod/DirectoryEnumerator.hpp"
+
 #ifdef _WIN32
 #include <windows.h>
 #else
@@ -5,10 +7,9 @@
 #include <dirent.h>
 #endif
 
+#include <cstring>
 #include <map>
 
-#include "nod/DirectoryEnumerator.hpp"
-
 namespace nod {
 
 DirectoryEnumerator::DirectoryEnumerator(SystemStringView path, Mode mode, bool sizeSort, bool reverse, bool noHidden) {