Reset Direct Mode in editorclass::reset()

There's a long-standing issue where the Direct Mode status of the loaded
custom map in memory never resets properly. So if you load a level with
a certain layout of Direct Mode rooms, that same layout will be
preserved if you start making a new level in the editor. This commit
fixes that issue.

desktop_version/src/editor.cpp

@@ -314,6 +314,7 @@ void editorclass::reset()
             level[i+(j*maxwidth)].enemyy1=0;
             level[i+(j*maxwidth)].enemyx2=320;
             level[i+(j*maxwidth)].enemyy2=240;
+            level[i+(j*maxwidth)].directmode=0;
         }
     }