#93745: Moved layer tree control package to a "controls" package and renamed the package from "layertrees" to "layerTree", the same as the folder. The layer tree control is now  aware of folders.
#93745: Moved Folder class to the layers package and made it mixin the LayerLoader system so we can load children layers.
#93745: Changes due package changes.
#93745: LayerLoader now sets the parent of a layer, which is the own loader, which, in turn, is a SMC.Map or a SMC.layers.Folder object (or any class mixing in SMC.LayerLoader).
WFSMarkerLayer overrides createNodeHTML so if it has no label, uses the WFS typeName as label.
#93745: Changed the test file for the layer tree.
#93745: Removed unnecesarry requires.
#93745: Removed unnecesary dependencies in the LayerTreeFolder class.
#93745: Fixed Folder class declaration.
#93745: Added some missing requires.
#93745: Added support for folder configuration shortcut (using type:"folder" in the layers configuration) and modified test.
Merge pull request #23 from luisromangz/93745-ImprovementsToStructureAndLayerTreeControl

#93745 improvements to structure and layer tree control