Ported From Old Project

Ported the QuadTree scene manager from the previous project.
Bug Fix

Fixed a bug in the VertexStream code.
A vertex buffer was not bound before applying a vertex element.
Ported Code

Ported more code from the old project.
Bug Fix

Fixed the vertex declarations of the terrain chunk vertex streams.
Fixed locking of the terrain chunks / terrain chunk storages.
Added a Frustum property in the camera class.
Ported the ISceneObject and IModel interface implementations, of the
TerrainChunk/TerrainChunkImpl classes, from the old code.
Extended the TerrainManager class with intersection and trace queries.
Bug Fix

As part of the previous fix.