Multiple domdoc and xmlDoc objects may need to share a common
properties object but may be released independently. So add a
reference count on the properties object.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=43377Signed-off-by: Francois Gouget <fgouget@codeweavers.com>
Signed-off-by: Nikolay Sivov <nsivov@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>