DisplayGrid: tidied up functions and created new functions to minimise unnecessary steps, added JavaDoc.
LabelPoint: list function moved from DisplayGrid.
visualinfo: added package-info.
DisplayGrid: re-organised function signatures to be consistent with other classes, added JavaDoc.
DisplayGrid: updated JavaDoc.
HeatMap: made function signatures consistent with others, added JavaDoc.
MatchMap: made function signatures consistent with others, added JavaDoc.