Move Set Town Start to Town menu and make it work the same as Set Out Start

- Also fix problem with initial starting town in new scenarios (it was uninitialized)

src/scenedit/scen.core.hpp

@@ -21,7 +21,6 @@ bool edit_make_scen_2(short& out_w, short& out_h, short& town_l, short& town_m,
 bool edit_make_scen_1(std::string& filename,std::string& title,bool& grass);
 void edit_scenario_events();
 bool build_scenario();
-void set_starting_loc();
 void edit_boats();
 
 bool check_range_msg(cDialog& me,std::string id,bool losing,long min_val,long max_val,std::string fld_name,std::string xtra);