Fixes #4583 by separating attachments to related and mixed multiparts
Fixes #4583 by separating attachments to related and mixed multiparts

Signed-off-by: Robert Angyal <27674ed0d737998332962477342c494d66594797@gmail.com>

Tpojka/CodeIgniter,ipabz/CodeIgniter,openset/ci,DiederikLascaris/CodeIgniter,smallp/CodeIgniter,ivantcholakov/CodeIgniter,tianhe1986/CodeIgniter,dhayalram123/CodeIgniter,andersonunsonst/CodeIgniter,poing/CodeIgniter,bcit-ci/CodeIgniter,gastongr/CodeIgniter,andersonunsonst/CodeIgniter,ganiutomo/CodeIgniter,Tpojka/CodeIgniter,ET-NiK/CodeIgniter,openset/ci,ipabz/CodeIgniter,Calico90/CodeIgniter,kala725/CodeIgniter-with-React,dhayalram123/CodeIgniter,openset/ci,andersonunsonst/CodeIgniter,madwings/InsaneDB,ivantcholakov/CodeIgniter,b1tc0re/CodeIgniter,ytetsuro/CodeIgniter,asmdigital/CodeIgniter,n054/CodeIgniter,butane/CodeIgniter,b1tc0re/CodeIgniter,dhayalram123/CodeIgniter,jim-parry/CodeIgniter,ytetsuro/CodeIgniter,butane/CodeIgniter,KeiroD/CodeIgniter,poing/CodeIgniter,asmdigital/CodeIgniter,Calico90/CodeIgniter,DiederikLascaris/CodeIgniter,bcit-ci/CodeIgniter,poing/CodeIgniter,Calico90/CodeIgniter,jim-parry/CodeIgniter,kala725/CodeIgniter-with-React,asmdigital/CodeIgniter,bcit-ci/CodeIgniter,ster/CodeIgniter,dhayalram123/CodeIgniter,Tpojka/CodeIgniter,ivantcholakov/CodeIgniter,ivantcholakov/CodeIgniter,b1tc0re/CodeIgniter,openset/ci,kamaslau/BasicCodeIgniter,KeiroD/CodeIgniter,DiederikLascaris/CodeIgniter,ster/CodeIgniter,Tpojka/CodeIgniter,madwings/InsaneDB,tianhe1986/CodeIgniter,ipabz/CodeIgniter,gastongr/CodeIgniter,KeiroD/CodeIgniter,ET-NiK/CodeIgniter,jim-parry/CodeIgniter,ytetsuro/CodeIgniter,tianhe1986/CodeIgniter,smallp/CodeIgniter,skullJ/CodeIgniter,kamaslau/BasicCodeIgniter,ET-NiK/CodeIgniter,DiederikLascaris/CodeIgniter,ytetsuro/CodeIgniter,butane/CodeIgniter,kala725/CodeIgniter-with-React,gastongr/CodeIgniter,ipabz/CodeIgniter,madwings/InsaneDB,gastongr/CodeIgniter,ganiutomo/CodeIgniter,bcit-ci/CodeIgniter,skullJ/CodeIgniter,megaspy/rental,kala725/CodeIgniter-with-React,tianhe1986/CodeIgniter,kala725/CodeIgniter-with-React,ipabz/CodeIgniter,andersonunsonst/CodeIgniter,Calico90/CodeIgniter,ET-NiK/CodeIgniter,ET-NiK/CodeIgniter,megaspy/rental,ytetsuro/CodeIgniter,ganiutomo/CodeIgniter,poing/CodeIgniter,KeiroD/CodeIgniter,butane/CodeIgniter,ster/CodeIgniter,openset/ci,madwings/InsaneDB,n054/CodeIgniter,jim-parry/CodeIgniter,asmdigital/CodeIgniter,ster/CodeIgniter,DiederikLascaris/CodeIgniter,tianhe1986/CodeIgniter,b1tc0re/CodeIgniter,Sproypef/CodeIgniter_AdminLTE2_Blade,ivantcholakov/CodeIgniter,kamaslau/BasicCodeIgniter,megaspy/rental,asmdigital/CodeIgniter,kamaslau/BasicCodeIgniter,megaspy/rental,b1tc0re/CodeIgniter,bcit-ci/CodeIgniter,n054/CodeIgniter,ster/CodeIgniter,ganiutomo/CodeIgniter,Tpojka/CodeIgniter,jim-parry/CodeIgniter,n054/CodeIgniter,skullJ/CodeIgniter,KeiroD/CodeIgniter,Sproypef/CodeIgniter_AdminLTE2_Blade,gastongr/CodeIgniter,madwings/InsaneDB,Sproypef/CodeIgniter_AdminLTE2_Blade,poing/CodeIgniter,ganiutomo/CodeIgniter,butane/CodeIgniter,n054/CodeIgniter,Calico90/CodeIgniter,Sproypef/CodeIgniter_AdminLTE2_Blade