Ends of roads are now cleaned up.

Roads at the end of the map (in both x and y directions) are either
closed off or removed based on how much is left over.
Parks can be placed now.

Parks are placed in random sections. They will currently overwrite
roads if the width is too wide. They are also always placed from the
bottom left.

Everything needs to be made more random.
PNG file is now consistent with array.

The array is stored with 0,0 as the top left, but the PNG file
output treats 0,0 as the bottom left. Just a quick fix so that
it is now consistent with how the array is stored.