+ICommitFileReader interface.
Now hands it off to the commit file reader. +test
+Real impl for CommitFileReader. Currently blank.
+Wireup for CommitFileReader.
+Reference for XAML for an upcoming test using App class.
+CommitDocument empty class.
+CommitDocument static property on App.
CommitFileReader now returns a CommitDocument.
Now stores the new commit document on the App class. +Test

Also moving the smarts into an else block, since Env.Exit() does not
act as a return statement in a test. It does for real, though!
+IFileAdapter interface.
+GitFileLoadException class.
AppController now exits if the specified file isn't found. +Test