More tests to use 'live' partitionning

The route file hyperlinking tests use the real partitionning.
Refactored the code to be able to use only the interesting part of the existing code.
Adds implementation of local rename for URI

Implements LocalRename handler.
RouteURI is in its own file.
RouteFile from test supports multiple markers.
Part of EditorHelpers from sdt.core is available in sdt.editor.

Fixes #84