Merge pull request #454 from molpopgen/cpp_iterator

Cpp iterator declarations.

Cython/Includes/libcpp/iterator.pxd

+#Basic reference: http://www.cplusplus.com/reference/iterator/
+#Most of these classes are in fact empty structs
+
+cdef extern from "<iterator>" namespace "std" nogil:
+    cdef cppclass iterator[Category,T,Distance,Pointer,Reference]:
+        pass
+    cdef cppclass output_iterator_tag:
+        pass
+    cdef cppclass input_iterator_tag:
+        pass
+    cdef cppclass forward_iterator_tag(input_iterator_tag):
+        pass
+    cdef cppclass bidirectional_iterator_tag(forward_iterator_tag):
+        pass
+    cdef cppclass random_access_iterator_tag(bidirectional_iterator_tag):
+        pass
+    
+    cdef cppclass back_insert_iterator[T](iterator[output_iterator_tag,void,void,void,void]):
+        pass
+    cdef cppclass front_insert_iterator[T](iterator[output_iterator_tag,void,void,void,void]):
+        pass
+    cdef cppclass insert_iterator[T](iterator[output_iterator_tag,void,void,void,void]):
+        pass
+    back_insert_iterator[CONTAINER] back_inserter[CONTAINER](CONTAINER &)
+    front_insert_iterator[CONTAINER] front_inserter[CONTAINER](CONTAINER &)
+    ##Note: this is the C++98 version of inserter.
+    ##The C++11 versions's prototype relies on typedef members of classes, which Cython doesn't currently support:
+    ##template <class Container>
+    ##insert_iterator<Container> inserter (Container& x, typename Container::iterator it)
+    insert_iterator[CONTAINER] inserter[CONTAINER,ITERATOR](CONTAINER &, ITERATOR)
+
+