Corrected spelling error in TacticalSymbols documentation.

git-svn-id: http://worldwind31.arc.nasa.gov/svn/trunk/WorldWind@2370 822214bb-dcf7-4c8d-a767-17ae0fb20d88
Modified the track airspace shape and the route airspace shape to display an optional dashed center line.

git-svn-id: http://worldwind31.arc.nasa.gov/svn/trunk/WorldWind@2371 822214bb-dcf7-4c8d-a767-17ae0fb20d88