General tidying up
Factored Grid out into a new module which hides implementation.
Ideally this shold not be specific to Life, but a general grid.
However, currently parsing is in here.
Reimplemented Grid to use 1d array
Fixed window sizing and rendering offset
Messing with XML
Switched to List monad
Switched to DList
Added type synonym
Switched to using cursor
Made XML output
Added example XML file
	A more point-free version
Fixed rendering offset properly