Added file-locking to interface
Added file-locking to interface

Now, the interface is thread-safe using lockfile. It is included in
documentation, and also a warning is issued when the module is not
available or could not be imported.

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