Rewrote SystemView architecture

ListWindow in SystemView completely restructured

Scrolling functionality seems to work in ListWindow now too
General additions in preparation for completed listWindow interactivity

Fleets, changing entTurnState
Created Removeable, Activatable interface

Extented ListWindow to create specialized windows for the game
Working construction, queueing, removal

More features to endTurn calculations, such as constructing and
deconstructing buildings

Creation of activityListWindow
Began working on fleets

Creation of some ships and ship objects

SystemView options added for fleet