Completed modification to assure continuity of
dvscf(G=0) for q->0.
For details see Phys RevB 82 165111 section III B

Not tested with PAW.

MCB


git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@10995 c92efa57-630b-4861-b058-cf58834340f0