oox: add support for the wps namespace

The plan is that once these are here, the writerfilter ooxml tokenizer
can refer to them. And then the writerfilter will call back to oox to do
the real drawingml import.

Change-Id: I1f860d1ade21cde767ad259d46b8d38ff167662f
writerfilter: tokenize wps:wsp

These are just the minimal changes, so that writerfilter calls into
oox::shape::ShapeContextHandler, which does the real work.

Change-Id: I4f44a508736d780ff090bca0d12526160ddd167f
oox: initial import of wps:wsp

We import something that's visible, but the shape is always inline, even
when it has to be anchored.

Change-Id: I6e20aa1a208f06731098ad21bb51c1ca840213d0
writerfilter: fix anchoring of anchored wps (drawingML) shapes

Previous code assumed that either we're dealing with VML shapes (where
the shape knows its position, anchoring, etc.) or with Wrtier pictures.
drawingML shapes are a third category: they don't know their anchoring
(and similar properties), still they are not Writer pictures.

For now just fix the anchoring, other properties should be handled in a
later follow-up commit.

Change-Id: I2fede3b11cfbd423cd50cfc0c032d424c81c6c4a