Since commit 2b5bf2f1
"graphic import improved" from 2006-11-20 by Oliver Specht,
there is an unused code reading pixel size (PROP_SIZE_PIXEL) of an
image in a part of GraphicImport::createGraphicObject() that imports
the wrap polygon.
When there's no PROP_SIZE100th_M_M in graphic, the imported wrap
polygon was simply dropped, and then automatic contour was generated
for graphic. Now we import contour correctly in this case.

Also, as paragraph background overlaps non-opaque graphics,
we need to set opaque to true regardless of behindDoc value of
wp:anchor.

Change-Id: Ifa5eec9f8ccaf5ba051732b6e4f965ae8606a1cf
Reviewed-on: https://gerrit.libreoffice.org/20103Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Meeks <michael.meeks@collabora.com>
Tested-by: Michael Meeks <michael.meeks@collabora.com>