Lab: Can now add/remove service references. (...)

- Added DebuggerDisplay attributes for: ServiceInfo, PluginInfo, LiveServiceInfo, LivePluginInfo, YodiiGraph, MockServiceReferenceInfo
- Edges are now observable
- Reference edges now bind to the reference's RunningRequirement
- Bugfix: Graph went haywire when a plugin had more than one ServiceReferences
- In PluginInfo: Added comparer lambda on CKObservableSortedArrayList creation for service references