Set higher precedence for .buildconf file in image directory
Set higher precedence for .buildconf file in image directory

Source .buildconf file in $IMGDIR last in order to prevent silently
overloading configuration by the less specific $TOPDIR/.buildconf.

Change-Id: Ia38101b6d4743b454dc2c8ba48d3b55af47ed53b

nihilifer/kolla,LoHChina/kolla,chenzhiwei/kolla,invenfantasy/kolla,LoHChina/kolla,dardelean/kolla-ansible,stackforge/kolla,invenfantasy/kolla,bdastur/kolla,negronjl/kolla,chenzhiwei/kolla,mrangana/kolla,rahulunair/kolla,meticulo3366/kolla,LoHChina/kolla,GalenMa/kolla,jakedahn/kolla,jakedahn/kolla,intel-onp/kolla,dardelean/kolla-ansible,negronjl/kolla,limamauricio/mykolla,openstack/kolla,HackToday/kolla,mandre/kolla,openstack/kolla,invenfantasy/kolla,mandre/kolla,coolsvap/kolla,rajalokan/kolla,limamauricio/mykolla,toby82/kolla,fdumpling/kolla,fdumpling/kolla,mandre/kolla,thetrav/kolla,tonyli71/kolla,GalenMa/kolla,meticulo3366/kolla,tonyli71/kolla,coolsvap/kolla,rajalokan/kolla,limamauricio/mykolla,rahulunair/kolla,rajalokan/kolla,HackToday/kolla,bdastur/kolla,stackforge/kolla,brk3/kolla,coolsvap/kolla,jakedahn/kolla,negronjl/kolla,nihilifer/kolla,dardelean/kolla-ansible,mrangana/kolla,fdumpling/kolla,chenzhiwei/kolla,thetrav/kolla,toby82/kolla,stackforge/kolla,brk3/kolla,toby82/kolla,HackToday/kolla,intel-onp/kolla