Add ProjectManager class
Extract copy logic from NewProject command
Refactor Project Loading Logic

Will initialize and strip audio if need be.

TODO:
-Change the way descriptions are loaded
-Change the way spaces are loaded
-Change how the project cache is generated
-Change how projects are closed.
Refactor Event Invokations
Merge branch 'valdev' into ProjectManager
Remove LoadingViewModel reference
set the is virtualizing property to scrollviewer to true
Merge branch 'master' of github.com:IMDC/LiveDescribe-Desktop
moved export to srt file to export file option
Add spaces and descriptions loading
Add Logging, event for auto-generated spaces

Also creates empty space and description files at the beginning of a
project to differentiate between a new project and one that is missing
files.
Add a LoadingViewModel field to ProjectManager
Add SaveProject method to ProjectManager
Move Space collection to ProjectManager class
Fix Project constructor call in ProjectFileTest
Merge branch 'master' of github.com:IMDC/LiveDescribe-Desktop into ProjectManager
Remove SpaceAdded Event
Remove Add Methods from SpaceCollectionViewModel
Remove Events from SpaceCollectionViewModel
Remove SpaceCollectionViewModel entirely