modemake.pl does not take into account constraints

[ckande]

Just a minor annoyance ...

The modemake.pl script does not seem to take into account of the 'Selective Dynamics' POSCARs.

[graeme]

Constrained atoms should not change position and so those degrees of freedom should be zero in the mode file.

Are you suggesting that we should explicitly zero those components even if they move between the two files?