Merge pull request #46 from michielvoo/u4-2417

U4-2417 Could the preview thumbnail link to the full image
Conflicts:
	src/Umbraco.Web/Umbraco.Web.csproj
	src/Umbraco.Web/umbraco.presentation/umbraco/controls/Images/ImageViewer.ascx.cs
	src/umbraco.editorControls/mediapicker/mediaChooser.cs