Some refactoring and first pass on StoryManager

Refactored IAuthorStorage and IReaderStorage into seperate package for
organization. Also added interfaces for listening to the model (current
story changed, current fragment changed and current story list changed).

Began implementing StoryManager. Nothing but skeleton code atm but it
should be enough to start putting together a controller for the user.
Reviewed story manager shell code

I think this is kinda ready for a pull request. Need a better idea of
interfaces available for getting data out of model before implementation
can go through.
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' of https://github.com/jesseDtucker/adventure.datetime
Merge pull request #45 from jesseDtucker/master

Skeleton code for StoryManager and UserController