org-odt.el: Support for anchoring an image to a page

org-odt.el: Support for anchoring an image to a page

* etc/styles/OrgOdtStyles.xml(OrgPageImage)
(OrgPageImageCaptionFrame): New styles for anchoring an image
centrally on a page.

* lisp/org-odt.el (org-odt-entity-frame-styles): Accommodate new
frame styles: \"OrgPageImage\" and \"OrgPageImageCaptionFrame\".
(org-export-odt-format-image): Handle frame-related :anchor,
:style and :attributes options attached to images as shown
below:
		[[./image.png]]
(org-odt-merge-frame-params): New. Auxiliary routine to merge
the default frame params and user-specified frame params.
(org-odt-format-entity): Use the above
`org-odt-merge-frame-params'.

Jérémy Compostella <jeremy.compostella@gmail.com> writes:
  I need to add pictures that are anchored to the \"page\" and not
  to the \"paragraph\". This is very useful to get a \"floating
  picture\" on an entire page without text breaks.

He also adds:
  Sometimes, you want to add a picture but you don't want a page
  break. For example, you want to add a big illustration. To
  render correctly, the picture needs its own page but you don't
  want to break the page. In this case you need to anchor the
  picture to the \"page\".

http://lists.gnu.org/archive/html/emacs-orgmode/2011-11/msg00869.html