Delete all commands on shutdown

Originally committed to SVN as r5473.

aegisub/src/command/command.cpp

@@ -107,4 +107,11 @@ namespace cmd {
 		init_tool();
 		init_video();
 	}
+
+	void clear() {
+		for (std::map<std::string, Command*>::iterator it = cmd_map.begin(); it != cmd_map.end(); ++it) {
+			delete it->second;
+		}
+		cmd_map.clear();
+	}
 }

aegisub/src/command/command.h

@@ -152,4 +152,7 @@ namespace cmd {
 	/// Retrieve a Command object.
 	/// @param Command object.
 	Command* get(std::string const& name);
+
+	/// Unregister all commands
+	void clear();
 } // namespace cmd

aegisub/src/main.cpp

@@ -334,6 +334,7 @@ int AegisubApp::OnExit() {
 	delete config::mru;
 	delete agi::hotkey::hotkey;
 	delete config::path;
+	cmd::clear();
 
 #ifdef WITH_AUTOMATION
 	delete global_scripts;