* Make conversions to and from Subversion's UTF-8 encoded strings more obvious,
using `_from_svn` and `_to_svn` functions
* The `_to_svn` enables also to clarify and simplify the code related to
scoped repositories
* A few other little fixes were needed in the modules
Note that content related issues are not addressed by this change
(the diff issues of #2905).
