[engine] Allow chained name_source
[engine] Allow chained name_source

FCP-INDI/nipype,grlee77/nipype,pearsonlab/nipype,Leoniela/nipype,sgiavasis/nipype,iglpdc/nipype,grlee77/nipype,mick-d/nipype,sgiavasis/nipype,blakedewey/nipype,mick-d/nipype,wanderine/nipype,dgellis90/nipype,gerddie/nipype,Leoniela/nipype,glatard/nipype,grlee77/nipype,FCP-INDI/nipype,blakedewey/nipype,dgellis90/nipype,carolFrohlich/nipype,iglpdc/nipype,carolFrohlich/nipype,JohnGriffiths/nipype,mick-d/nipype,wanderine/nipype,sgiavasis/nipype,arokem/nipype,glatard/nipype,FCP-INDI/nipype,dgellis90/nipype,wanderine/nipype,gerddie/nipype,pearsonlab/nipype,gerddie/nipype,glatard/nipype,arokem/nipype,Leoniela/nipype,JohnGriffiths/nipype,carolFrohlich/nipype,pearsonlab/nipype,mick-d/nipype,FCP-INDI/nipype,blakedewey/nipype,wanderine/nipype,dgellis90/nipype,carolFrohlich/nipype,JohnGriffiths/nipype,iglpdc/nipype,arokem/nipype,grlee77/nipype,blakedewey/nipype,iglpdc/nipype,pearsonlab/nipype,JohnGriffiths/nipype,gerddie/nipype,arokem/nipype,sgiavasis/nipype,glatard/nipype