Always show SavedBy panel in MetaDataViewer

Conflicts:
	components/insight/SRC/org/openmicroscopy/shoola/agents/metadata/view/MetadataViewerComponent.java
	components/insight/SRC/org/openmicroscopy/shoola/agents/metadata/view/MetadataViewerUI.java
Show SavedBy selection
Mark the current rendering setting in the SavedBy view

Conflicts:
	components/insight/SRC/org/openmicroscopy/shoola/agents/metadata/view/MetadataViewerUI.java
	components/insight/SRC/org/openmicroscopy/shoola/env/rnd/PixelsServicesFactory.java
	components/insight/SRC/org/openmicroscopy/shoola/env/rnd/RndProxyDef.java
Just did some code clean up and dcoumentation
Removed SavedBy action from the toolbar
Reload the viewedby thumbnails after new rendering settings were applied
Some minor fixes
Fix: MetadataViewerAgent not updating thumbnails

MetadataViewerAgent now listens to rendering settings changes of the
ImageViewer's rendering panel
Update rendering settings thumbnails on change
Fixed NPE if renderer has not been set yet
Fixed a typo
Fix: ViewedBy-Pane not reloaded after creation of new RenderingDefiniton
Fix: New created RenderingDefintions were not marked as selected
Avoid potential NPE
Fix exception when viewing a well sample.
Only load viewed by when the renderer is loaded.
Review code to use new getImage method.
Fixed a potential NPE
Merge pull request #2697 from dominikl/rebased/dev_5_0/saved_by_display_3

Rendering settings: Always show 'SavedBy' Panel (rebased onto dev_5_0)