updated Graph.draw_isolines function to use the IsoLines.draw_isolines function
cleaned up IsoLines.__set_axis_limits code
fixed missing function declaration
cleaned up IsoLines.get_isolines code
fixed correct function name usage
created a common module for common functions between the IsoLines and Graph classes
added inheritances from Common.BasePlot to IsoLines and Graph
moved Graph and IsoLines dictionary maps to BasePlot
moved IsoLines.__init__ exception handling to BasePlot
moved common IsoLines and Graph properties to BasePlot
moved _getSatLines to BasePlot.__get_sat_lines
moved _satBounds to BasePlot.__sat_bounds
deleted _getIsoLineLabel and created a Symbol_Map in BasePlot
fixed call of BasePlot._get_sat_lines function
moved IsoLines.__get_isolines_data to BasePlot.__get_isolines_data
removed show function - added to Graph class
moved module test code under "__main__" to a Tests module
fixed error with duplicate figures
fixed call to _get_sat_lines function