Add support for int64 and uint64 as it was done in Schweizer-Messer

See https://github.com/ethz-asl/Schweizer-Messer

gtsam/3rdparty/numpy_eigen/include/numpy_eigen/type_traits.hpp

@@ -28,6 +28,31 @@ template<> struct TypeToNumPy<int>
   }
 };
 
+template<> struct TypeToNumPy<boost::int64_t>
+{
+  enum { NpyType = NPY_LONG };
+  static const char * npyString() { return "NPY_LONG"; }
+  static const char * typeString() { return "long"; }
+  static bool canConvert(int type)
+  {
+    return type == NPY_INT || type == NPY_LONG;
+  }
+};
+
+template<> struct TypeToNumPy<boost::uint64_t>
+{
+  enum { NpyType = NPY_UINT64 };
+  static const char * npyString() { return "NPY_UINT64"; }
+  static const char * typeString() { return "uint64"; }
+  static bool canConvert(int type)
+  {
+    return type == NPY_UINT8 || type == NPY_USHORT ||
+           type == NPY_UINT16 || type == NPY_UINT32 || 
+           type == NPY_ULONG || type == NPY_ULONGLONG || 
+           type == NPY_UINT64;
+  }
+};
+
 template<> struct TypeToNumPy<unsigned char>
 {
   enum { NpyType = NPY_UBYTE };