renamed DescriptionViewModel to DescriptionCollectionViewModel
renamed SpacesViewModel to SpaceCollectionViewModel
Add DialogShower Factory class

Spawns dialog windows and returns their viewmodels
Merge branch 'master' of github.com:IMDC/LiveDescribe-Desktop
Merge branch 'master' of github.com:IMDC/LiveDescribe-Desktop into valdev

Conflicts:
	LiveDescribe/LiveDescribe/ViewModel/DescriptionInfoTabViewModel.cs