Big refactor, shuffling a lot of files around

src/util/filesystem_.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <filesystem>
+#include <string>
+
+namespace anm2ed::util::filesystem
+{
+  std::string path_preferences_get();
+  bool path_is_exist(const std::string&);
+  bool path_is_extension(const std::string&, const std::string&);
+
+  class WorkingDirectory
+  {
+  public:
+    std::filesystem::path previous;
+
+    WorkingDirectory(const std::string&, bool = false);
+    ~WorkingDirectory();
+  };
+}