Refactor: Moved editable map elements into Map

Upon instantiation a Map is initially configured in editable mode.
The map edit API calls Map::endEditing() to signal that editing has
completed. At which point the new map elements are transferred from
the editable element lists, a BSP is built (todo: defer this) and
the map is switched to non-editable mode.

Todo: Cleanup.

doomsday/client/include/world/map.h

@@ -87,6 +87,9 @@ class Map
     DENG2_ERROR(MissingLightGridError);
 #endif
 
+    /// Base error for runtime map editing errors. @ingroup errors
+    DENG2_ERROR(EditError);
+
     typedef QList<Vertex *> Vertexes;
     typedef QList<Sector *> Sectors;
     typedef QList<Line *> Lines;
@@ -149,6 +152,19 @@ class Map
 
     int _ambientLightLevel; // Ambient lightlevel for the current map.
 
+    struct EditableElements
+    {
+        Map::Vertexes vertexes;
+        Map::Lines lines;
+        Map::Sectors sectors;
+        Map::Polyobjs polyobjs;
+
+        /// Map entities and element properties (things, line specials, etc...).
+        EntityDatabase *entityDatabase;
+
+        EditableElements() : entityDatabase(0) {}
+    } editable;
+
 public:
     Map();
     ~Map();
@@ -761,6 +777,30 @@ class Map
 
 #endif // __CLIENT__
 
+public:
+    /*
+     * Runtime map editiing:
+     */
+
+    /// @return @c true= a new BSP was built successfully for the map.
+    bool endEditing();
+
+    Vertex *createVertex(Vector2d const &origin,
+                         int archiveIndex = MapElement::NoIndex);
+
+    Line *createLine(Vertex &v1, Vertex &v2, int flags = 0,
+                     Sector *frontSector = 0, Sector *backSector = 0,
+                     int archiveIndex = MapElement::NoIndex);
+
+    Sector *createSector(float lightLevel, Vector3f const &lightColor,
+                         int archiveIndex = MapElement::NoIndex);
+
+    Polyobj *createPolyobj(Vector2d const &origin);
+
+    void clearEditableElements();
+
+    void pruneEditableVertexes();
+
 private:
     DENG2_PRIVATE(d)
 };