GEOS5547 - GSIP84 - LayerGroup: added Mode, RootLayer and RootLayerStyle. Updated WMS GetCapabilities and GetMap
GEOS5547 - fixed backward compatibility for serialized layer groups
GEOS5547 - fixed PreviewLayerProvider
GEOS5547 - fixed LayerGroup Container exception in GetMapKvpRequestReader
GEOS5547 - UI: improved LayerGroup Root Layer style selection
GEOS5547 - added test to CatalogBuilderTest
GEOS5547 - wms: removed TODO comment
GEOS5547 - UI: hidden Root Layer form when LayerGroup is not in EO mode
GEOS5547 - fixed LayerGroup REST issue
GEOS5547 - improved UI
Merge pull request #99 from svzdvd/GEOS-5547

GEOS5547 - GSIP84 - LayerGroup: added Mode, RootLayer and RootLayerStyle...
Merge branch 'master' of git://github.com/geoserver/geoserver