[selectors, facet] make is_instance and other EClassSelector subclass gather entity classes from 'select' and 'filtered_variable' context information. Closes #1796732
This allow for instance to use the filter form on rqlst where the filtered variable is not selected
/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 2>&1; \
else \
/etc/init.d/cubicweb reload > /dev/null 2>&1; \
fi; \
endscript
}