Populate $oldSlug from $changeSet
Populate $oldSlug from $changeSet

Populating $oldSlug from $changeSet original value rather than from
$object. $object holds the new value at this stage. This meant that
other preUpdate event handlers could not see the original value.

nirav-programmer/DoctrineExtensions,tomazahlin/DoctrineExtensions,rubenrua/DoctrineExtensions,jeroendesloovere/DoctrineExtensions,gadelkareem/DoctrineExtensions,jmcclell/DoctrineExtensions,lengpiseth/DoctrineExtensions,sroze/DoctrineExtensions,stof/DoctrineExtensions,notrix/DoctrineExtensions,pmishev/DoctrineExtensions,mablae/DoctrineExtensions,tyx/DoctrineExtensions,birko/DoctrineExtensions,CiscoVE/DoctrineExtensions,teohhanhui/DoctrineExtensions,hhjcz/DoctrineExtensions,Engerim/DoctrineExtensions,SocialbitGmbH/DoctrineExtensions,Preis24/DoctrineExtensions,aplysie/DoctrineExtensions,marc-j/DoctrineExtensions,Padam87/DoctrineExtensions,edigu/DoctrineExtensions,l3pp4rd/DoctrineExtensions,bocharsky-bw/DoctrineExtensions,eliberty/DoctrineExtensions,aramalipoor/DoctrineExtensions,blazarecki/DoctrineExtensions,cmfcmf/DoctrineExtensions,anesse/DoctrineExtensions,lafourchette/DoctrineExtensions,akd3vs/DoctrineExtensions,Viburnum/DoctrineExtensions