Rename edentities to CustomEntity

That's what it is - it's an entity in a custom level. Not something to
do with the editor, necessarily. Like before, the name of the XML
element will remain the same.

desktop_version/src/CustomLevels.cpp

@@ -1073,7 +1073,7 @@ bool customlevelclass::load(std::string& _path)
         {
             for( tinyxml2::XMLElement* edEntityEl = pElem->FirstChildElement(); edEntityEl; edEntityEl=edEntityEl->NextSiblingElement())
             {
-                edentities entity = edentities();
+                CustomEntity entity = CustomEntity();
                 const char* text = edEntityEl->GetText();
 
                 if (text != NULL)