Add missing includes to xdynamic_bitset.hpp

#include <initializer_list> for std::initializer_list
#include <memory>  for std::allocator
#include <algorithm> for std::copy

include/xtl/xdynamic_bitset.hpp

@@ -13,6 +13,10 @@
 #include <climits>
 #include <type_traits>
 #include <vector>
+#include <initializer_list>
+#include <iterator>
+#include <memory>
+#include <algorithm>
 
 #include "xclosure.hpp"
 #include "xspan.hpp"