Expand on text field keyboard shortcuts

- Clipboard support
- Text will now wrap when a word is longer than the width of the destination rect (doesn't just apply to text fields, but is most relevant there)
- Edit menu stub added in scenario editor code
- Rich text keys (eg cut, copy, paste, select all) are no longer processed by the dialog itself; only the text field processes them; this just means that if they were set as button equivalents they would no longer work (you'd have to set the raw equivalent instead, eg ctrl+C instead of copy).
- Text fields now rely on SFML's TextEntered event for actual input - the practical result of this is that your keyboard layout is honoured (though non-ASCII characters just display as boxes).
- In a similar vein, shift is not auto-applied to the input keys, so you'd have to set shift+2 instead of @ as the key equivalent (this actually fixes some stuff, such as in the spellcasting dialog, since I was already setting shift+2 instead of @).

osx/scenedit/scen.main.cpp

@@ -58,6 +58,7 @@ void Handle_Update();
 void handle_menu_choice(long choice);
 void handle_apple_menu(int item_hit);
 void handle_file_menu(int item_hit);
+void handle_edit_menu(int item_hit);
 void handle_scenario_menu(int item_hit);
 void handle_town_menu(int item_hit);
 void handle_outdoor_menu(int item_hit);
@@ -269,6 +270,25 @@ void handle_file_menu(int item_hit) {
 	}
 }
 
+void handle_edit_menu(int item_hit) {
+	// Currently, this merely passes appropriate input to the frontmost dialog.
+	// TODO: Handle edit menu operations when no dialog is onscreen.
+	cKey key = {true};
+	switch(item_hit) {
+		case 1: key.k = key_undo; break;
+		case 2: key.k = key_redo; break;
+		case 4: key.k = key_cut; break;
+		case 5: key.k = key_copy; break;
+		case 6: key.k = key_paste; break;
+		case 7: key.k = key_del; break;
+		case 8: key.k = key_selectall; break;
+	}
+	if(!cDialog::sendInput(key)) {
+		// Handle non-dialog edit operations here.
+		switch(key.k) {}
+	}
+}
+
 void handle_scenario_menu(int item_hit) {
 	short i;
 	fs::path file;