enh: added ability to get list of node names in a workflow
enh: added ability to get list of node names in a workflow

grlee77/nipype,pearsonlab/nipype,dgellis90/nipype,rameshvs/nipype,christianbrodbeck/nipype,fprados/nipype,FCP-INDI/nipype,FredLoney/nipype,mick-d/nipype_source,mick-d/nipype,gerddie/nipype,arokem/nipype,mick-d/nipype_source,arokem/nipype,FCP-INDI/nipype,blakedewey/nipype,grlee77/nipype,JohnGriffiths/nipype,carlohamalainen/nipype,FCP-INDI/nipype,Leoniela/nipype,rameshvs/nipype,dgellis90/nipype,carlohamalainen/nipype,rameshvs/nipype,pearsonlab/nipype,rameshvs/nipype,carolFrohlich/nipype,carlohamalainen/nipype,christianbrodbeck/nipype,Leoniela/nipype,glatard/nipype,iglpdc/nipype,iglpdc/nipype,pearsonlab/nipype,carolFrohlich/nipype,glatard/nipype,JohnGriffiths/nipype,arokem/nipype,glatard/nipype,dmordom/nipype,sgiavasis/nipype,gerddie/nipype,gerddie/nipype,blakedewey/nipype,JohnGriffiths/nipype,carolFrohlich/nipype,iglpdc/nipype,grlee77/nipype,carolFrohlich/nipype,mick-d/nipype,sgiavasis/nipype,mick-d/nipype,FredLoney/nipype,FredLoney/nipype,glatard/nipype,dgellis90/nipype,FCP-INDI/nipype,wanderine/nipype,pearsonlab/nipype,blakedewey/nipype,arokem/nipype,dmordom/nipype,sgiavasis/nipype,wanderine/nipype,iglpdc/nipype,fprados/nipype,blakedewey/nipype,wanderine/nipype,mick-d/nipype_source,grlee77/nipype,JohnGriffiths/nipype,mick-d/nipype,sgiavasis/nipype,Leoniela/nipype,dgellis90/nipype,wanderine/nipype,gerddie/nipype,dmordom/nipype,fprados/nipype