Update Docking folder from MonoDevelop
Updated Docking: Some adjustments

Remove unused files.
Set default style, draw black on black is not really good.
Remove warnings (e.g. unused variables)
Add icons used for the component tab
Move VirtualListView to Docking.Components
Add some icons for the example components.
Adjust handling of components should never hidden but closed
Remove unneeded exception, remove get text (not supported)
Create tab icons using extended IComponentFactory.

Need access to the icons without existing instance.
Set menu item icon, but not yet visible