In Word it is not allowed to anchor a shape to
an onther shape.
That's why this code write text boxes only on the first level,
nested frames is also written out on the same level because
writeDMLText/WriteVMLText will push nested frames
into m_aFramesOfParagraph's back.

Change-Id: Ie1956ac9ac0ed56ff9611ff9763eb454f02558b9