Comment 3 for bug 1043571

The patch in attachment should fix four memory leaks related to not releasing memory occupied by sp_repr_css_write_string.
Hopefully this patch does not lead to errors such as in the reverted revision.

Can someone check with valgrind whether it solves the above bug? I can not check and I'm not sure ... If it does not solve the issue, then quite probably the culprit is that the memory occupied by share_string on line 375 of xml/simple-node.cpp (new_value = share_string(cleaned_value);) is not released.