Always check whether a model be a subclass of CI_Model when loaded.
Always check whether a model be a subclass of CI_Model when loaded.

Signed-off-by: tianhe1986 <281d452b19a59ed794600af3f9379854f1230d4f@163.com>

ipabz/CodeIgniter,poing/CodeIgniter,ipabz/CodeIgniter,ipabz/CodeIgniter,jim-parry/CodeIgniter,jim-parry/CodeIgniter,poing/CodeIgniter,jim-parry/CodeIgniter,ganiutomo/CodeIgniter,madwings/InsaneDB,bcit-ci/CodeIgniter,kamaslau/BasicCodeIgniter,asmdigital/CodeIgniter,Tpojka/CodeIgniter,ytetsuro/CodeIgniter,kamaslau/BasicCodeIgniter,asmdigital/CodeIgniter,asmdigital/CodeIgniter,butane/CodeIgniter,ytetsuro/CodeIgniter,tianhe1986/CodeIgniter,tianhe1986/CodeIgniter,ytetsuro/CodeIgniter,ganiutomo/CodeIgniter,madwings/InsaneDB,Tpojka/CodeIgniter,openset/ci,tianhe1986/CodeIgniter,openset/ci,butane/CodeIgniter,asmdigital/CodeIgniter,poing/CodeIgniter,butane/CodeIgniter,Tpojka/CodeIgniter,jim-parry/CodeIgniter,kamaslau/BasicCodeIgniter,ytetsuro/CodeIgniter,Tpojka/CodeIgniter,ytetsuro/CodeIgniter,butane/CodeIgniter,butane/CodeIgniter,smallp/CodeIgniter,kamaslau/BasicCodeIgniter,openset/ci,ganiutomo/CodeIgniter,poing/CodeIgniter,madwings/InsaneDB,jim-parry/CodeIgniter,Tpojka/CodeIgniter,ganiutomo/CodeIgniter,bcit-ci/CodeIgniter,ganiutomo/CodeIgniter,bcit-ci/CodeIgniter,madwings/InsaneDB,smallp/CodeIgniter,ipabz/CodeIgniter,openset/ci,openset/ci,tianhe1986/CodeIgniter,tianhe1986/CodeIgniter,asmdigital/CodeIgniter,ipabz/CodeIgniter,madwings/InsaneDB,bcit-ci/CodeIgniter,bcit-ci/CodeIgniter,poing/CodeIgniter