Made TriplePlay wrappers more robust, support for percentages parent sizes.

Given TP doesn't have notions of min and max sizes, I had initially made all those required methods in the wrapper return preferredSize. This doesn't work for percentages, as the miglayout Grid will then prevent the parent's available space from being utilized as the MaxSize (available) will be clipped to PreferredSize. Moreover, I hadn't really understood how the hints were a consequence of Michael's one pass layout approach. A MigLayout container cannot be allowed to make requests of it's parent for sizing information, as the parent in TP wont' have that information until the children are fully laid out. MigGroup alleviates this by returning the TP hints to MigLayout when it's TP preferredSize has not yet been calculated and is invalid.