Add example 8 to the list of working examples.
Add functions necessary to get example 8 to work.
Fix indexing bug that was causing memory faults.
Change with-foreign-grid argument order to match with with-foreign-matrix. Fix pl-length function so that it returns the length when list-or-null when it is an array.
Remove comment explaining the macro for the time being.
Change to match new argument order for with-foreign-grid.