[etwist] pass the repository to the root resource
This is another step toward a cleaner instantiation scheme for the repo.
The http test now pass an already created object to the etwist server instead of
relying on the config cache.
Related to #2249513
Document: cubicweb-doc
Title: CubicWeb documentation
Author: Logilab
Abstract: Some base documentation for CubicWeb users and developpers
Section: Apps/Programming
Format: HTML
Index: /usr/share/doc/cubicweb-documentation/index.html
Files: /usr/share/doc/cubicweb-documentation/*.html