There were multiple issues here:

- convertEmuToHmm() not handling negative values
- position:absolute style property being ignored
- mso-position-vertical-relative is not converted to
  text::RelOrientation
- SwAnchoredDrawObject::_SetPositioningAttr() re-positioning already
  positioned objects
- DomainMapper_Impl::PushShapeContext() inserting positioned objects as
  character