FIX #2399 new feature WPT visited marking

Hi, I have implemented this new function. waypoints can be now marked as visited. When they are marked ... they will have another title color in wpts list and transpoarent marker background on live map.

You can see screenshots here:
http://i.imgur.com/ibnVPnZ.png
http://i.imgur.com/ER0dQr8.png
http://i.imgur.com/QJGSkO5.png

Feel free to comment or provide different graphics.