mapfishapp: quick client side part for #751
send more information to GN service
fixed POST body
Mapfishapp - indenting XML documents before save

This aims to save documents properly indented in db, for better
readability (assuming XML is sufficiently human-readable ...). This
shall make the debugging easier, when trying to read returned WMC.

Feedback welcome (poke @fvanderbiest) ; I think it is a good move to
also have an implicit XML validation server-side.
take into account service endpoint + POST body format
Merge remote-tracking branch 'origin/master' into issue751

Conflicts:
	mapfishapp/src/main/webapp/app/js/GEOR_util.js
mapfishapp - issue 751 - Content-Type mismatch

OpenLayers expect to send xml by default, here we are sending plain
text url-encoded parameters. Jeeves act differently if XML is
explicitely declared in the headers.
Merge pull request #824 from georchestra/issue751

Issue751