Add mathjs to node.sh, update comments.
Merge branch 'master' of https://github.com/tobinquadros/dotfiles

* 'master' of https://github.com/tobinquadros/dotfiles: (5 commits)
  Better comments and README.md.
  Improve pmset, turn-off bluetooth, add restart option.
  Remove redundant helpers and util functions.
  ...