added option '--npm'; fixed 'freeze' for npm >= 1.0.X;
added option '--npm'; fixed 'freeze' for npm >= 1.0.X;

jamesblunt/nodeenv,Milstein/nodeenv,chriskuehl/nodeenv,asottile/nodeenv,twmt/nodeenv,simudream/nodeenv,simudream/nodeenv,asottile/nodeenv,twmt/nodeenv,Milstein/nodeenv,jhermann/nodeenv,jamesblunt/nodeenv,chriskuehl/nodeenv