Some dynamic strings (e.g. loaded image paths) may contain XML special
characters which breaks parsing.

Fix this by escaping all dynamic strings (i.e. character data and
attribute values) that go into the XML replies.
Signed-off-by: Jinoh Kang <jinoh.kang.kr@gmail.com>
Signed-off-by: Rémi Bernon <rbernon@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>