Convert charm back to using non-legacy node ppa
With reference to https://launchpad.net/~chris-lea/+ppa-packages .
The only behavioral change is in the third chunk of hooks/utils.py ,
the rest is just code reformatting to appease Sublime Text, and some
additional docstrings.
R=frankban, gary.poster
CC=
https://codereview.appspot.com/8837048