Backout "[entity,storage] remove hackish code from the bfss path The merge of the repo-side and web-side entity caches doesn't actually work, because entities have a _cw attribute which is sometimes a connection and sometimes a web request, and whose nature changes not-really-predictably whenever ResultSet.get_entity() is called and brings it out of the cache. This reverts commit 59a79300f213.

usr/lib/python2*/*-packages/cubicweb/web
usr/lib/python2*/*-packages/cubicweb/wsgi
usr/share/cubicweb/cubes/shared/data
usr/share/cubicweb/cubes/shared/wdoc