Error message bei EUMETSAT server for non-available stereographic projections unhelpful

[Joern Ungermann]

Instead of a textual error message of the server some internal error with object conversion is shown.

[Reimar Bauer]

Made recognition of service exception XML more robust

Service exeption info tag bei eumetsat had a utf tag that interfered with the recognition of the service expcetion which was instead interpreted as an image.

Fix issue #318

→ <<cset e8a931624b2e>>