GWTII-167: First implementation of rendering with TileQueue.
GWTII-167: Fixed map not rendering correctly in the beginning.
GWTII-167: Checkstyle and javadoc.
GWTII-167: Checkstyle and javadoc.
GWTII-167: Checkstyle and javadoc.
GWTII-167: Moved TileQueue etc. to impl.
GWTII-167: Fixed bug where map wouldn't load if queue emptied too fast.
GWTII-167: Decoupled DomTile and HtmlImageImpl.
GWTII-167: Removed commented code.