downgrade nan dependency
downgrade nan dependency

As of 1.6.1 there is a bug preventing compilation
with at least io.js 1.0.4.

mscdex/mmmagic,mscdex/mmmagic,mscdex/mmmagic,thejinx0r/mmmagic,Gobella/mmmagic,thejinx0r/mmmagic,Gobella/mmmagic,thejinx0r/mmmagic,Gobella/mmmagic