Internally use C++ type 'long long', instead of 'long', for properties of (graphml) type 'long'

This will increase memory usage, but guarantees, across different
platforms, that 'long' will always hold larger values than 'int'.

src/boost-workaround/boost/graph/graphml.hpp

@@ -181,7 +181,7 @@ class mutate_graph_impl : public mutate_graph
 protected:
     MutableGraph& m_g;
     dynamic_properties& m_dp;
-    typedef mpl::vector<bool, int, long, float, double, std::string> value_types;
+    typedef mpl::vector<bool, int, long long, float, double, std::string> value_types;
     static const char* m_type_names[]; 
 };
 

src/graph/graph_properties.hh

@@ -35,11 +35,11 @@ std::ostream& operator<<(std::ostream &o, const pos_t &p );
 std::istream& operator>>(std::istream &o, pos_t &p );
 
 // global property types
-typedef boost::mpl::vector<bool, int, long, size_t, float, double, std::string, pos_t> value_types;
+typedef boost::mpl::vector<bool, int, long long, size_t, float, double, std::string, pos_t> value_types;
 extern const char* type_names[];
 
 // scalar types
-typedef boost::mpl::vector<bool, int, long, size_t, float, double> scalar_types;
+typedef boost::mpl::vector<bool, int, long long, size_t, float, double> scalar_types;
 extern const char* scalar_names[];