New png plotting set-ups in daily RDAHMM service

In daily RDAHMM service, we modified some of the gnuplot scripts so that the png pictures are plotted in the following manner:

(1) All points are first connected with light gray lines;
(2) On top of the gray lines, continuous sections with the same state are plotted with lines of colors corresponding to the state;
(3) On top of the colored lines, all points are plotted with "+"-shaped points of colors corresponding to the states of each point.