FormPrintout : clean a bit code
FormPrintout._replaceXmlByForm : change the xpath expression to get the node
from one level higher. In this way we can have all the node tree used for the
field. Add style in style dict for this node
FormPrintout._createOdfUniqueFileName : use quote_plus in both cases, add a comment to explain it
ImageField : add a method _replaceImage used to replace an image in an odg file
FormPrintoutAsODG : add test for proxyfields
Formulator.Field, Formulator.Widget : change render_odg signature to accept
more parameters required for image mapping. Add First level node.
ERP5OOo/tests/test_document/Foo_001.odg add some descriptions arround fields, to make easier to understand the purpose
of each element in the document.

reviewed and approved by Romain

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@31339 20353a03-c40f-0410-a6d1-a30d3c3de9de