This method creates a new point for the agent to be placed randomly within the
urban area using JTS CoordinateArrays class
http://vividsolutions.com/jts/javadoc/com/vividsolutions/jts/geom/CoordinateArrays.html.
Used to remove an agent at the moment it is only used when an
agent becomes to old ie 65+
BasicPointAgents are removed but their index (gisAgentIndex
is not altered.