docx: List style - Inherit selected text-properties of the paragraph mark.

* The text-properties of the paragraph mark are below text-properties
of the list style in the hierarchy tree. Apply them properly before
removal. We can not save them as text-properties of the paragraph
style because they don't alter formatting of text chunks.

* Initialize the ParagraphBulletProperties instance properly.

* A numbered list in MSWord inherits both Boldness and Italics.

Consider this patch as addition to the following commit, where the
inheritance tree was broken:
docx: Write text-properties only in case of empty paragraphs.
commit 04e59e47bb8d67188078946877edb0d5bd3d9ef3