Implemented SmallIcon binding for DSFunctionNodeSearchElement
Added resources to DSCoreNodes to show some images. Color and File classes
Added images to Resources folder
Reverted untouched files
NodeSearchElement. SmallIcon property  implemented.
Icon for class button added.
removed dead comments; Auto size of icons removed, now 32x32
decorations: remove empty lines, change comments etc.
icons divided in 2 different folders: DSCoreNodes and DSCoreNodesUI
Added small icons and images.resx to next Projects:
- CoreNodes
- CoreNodesUI
- IronPythonUI
- DynamoCore

Warning: some of nodes wasn't found, find out it later.
Not found nodes:
1) DSCore.List: CartesianProduct, Combine, Filter.
2) DSCore.Logic: And, If, Or.
Added small icons for DSOffice project.
Icons for DSIronPythonNode and DynamoCore moved in folder "SmallIcons".
Added images for class buttons.
+ icons for Project "DynamoWatch3D"

Warning: couldn't find icons for "Types" and "Watch 3D".
Merge remote-tracking branch 'remotes/origin/Sitrus2' into DUI-IconsAddition
Changes just for BrowserInternalElement:
- assembly renamed into resourceAssembly;
- added enum ResourceType;
- Assembly renamed into ResourceAssembly.
removed set from BrowserInternalElement's SmallIcon
Changes for NodeSearchElement:
- removed _assembly & Assembly;
- added protected override string GetResourceName;
Changes for DSFunctionNodeSearchElement:
- removed BitmapImage SmallIcon;
- added protected override string GetResourceName.
All generating name of icon removed to BrowserInternalElement, now we do not need methods like GetSmallIcon and GetLargeIcon in LibraryCustomization.
Decorations:
- added comments;
- assembly renamed into resourceAssembly.
Decorations:
- removed empty string;
- long lines divided.