backport stable branch and some vreg cleanups:
* move initialization_completed from cwvreg to base VRegistry class
allowing simplification of CWVregistry
* cleanup initialization process: __registered__ is now called after
initialization completed, by the relevant registry.
* fix/remove deprecated tests
/var/log/cubicweb/*.log {
weekly
missingok
rotate 10
compress
delaycompress
notifempty
create 640 root adm
sharedscripts
postrotate
if [ -x /usr/sbin/invoke-rc.d ]; then \
invoke-rc.d cubicweb reload > /dev/null; \
else \
/etc/init.d/cubicweb reload > /dev/null; \
fi; \
endscript
}