Combined SelectionLoader with SelectionHandler.  Now, SelectionHandlers can only deal with a single type of Selection.
Abstracted the selections system a bit more than what it was previously by adding the 'CommandableSelections' and 'SelectableSelections' interfaces.
Moved the selections code to the 'api' side of Gamegine.
Renamed #getSelectionWand() to #getGlobalWand().
Commented out #getPlayerSelection(Player) and #createPlayerSelection(Player) as I plan on implementing a different method of creating selections that involves the 'CommandableSelections' and 'SelectableSelections' interfaces.
Uncommented #getPlayerSelection(Player) as this method will still be used.  Only the creation of selections will be handled differently.
Added a #getDescription() method to return the description of the selection handler.
Finished up the CommandableSelections class
Thought I named this correctly, but apparently not.
Finished up the selections API for selections that are created via a command.