Resource names may be specified as '/' separated strings
Add unicode support for cern.resource.*

This correctifies the handling of input encoding for resources. Encoding
should almost always be cared about most directly before/after IO, such
that the program internally handles only text (unicode). It makes
therefore sense to provide encoding paramaters to the open/load methods.

TODO: The CouchResourceProvider has not been checked to handle encoding
correctly and is probably broken in the current implementation.