DOCX export: nested text frames

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
DOCX import: floating tables belong to the same paragraph

When two floating tables were belong to the same paragraph,
import makes one of them anchored to the other instead of
anchorig both to the corresponding paragraph.

Modifications:
- Check the whole text range for anchored frames not
just one point of it.
- Save frame format's name because SwFrmFmt pointers can
become invalid.

Change-Id: Ide7c894065b619095a8e713ff0622bbea4f199b6
drawingML export: make WritePolyPolygon robuster

Make sure a:cubicBezTo conatins three a:pt elements.

escherex: It seems a cubic bezier curve last point has
a POLY_NORMAL flag and not POLY_CONTROL.

Change-Id: Id6dc2160c7ae171a720e4a1aa9161cef2b3b9413