Preliminary Node and npm support on master

[Richard Crowley]

Good news for the Node nerds among us! Just in time for the Node
Knockout [1], I've added preliminary support for npm [2] to Blueprint.
There are a couple of caveats, however, this being brand new.

First, the easiest and most supported supported way to install Node
itself is via Chris Lea's Ubuntu PPAs, which he maintains for the
0.4.x series [3] and 0.5.x series [4] of Node itself. To install Node
and npm this way, do the following:

echo "deb http://ppa.launchpad.net/chris-lea/node.js/ubuntu
$(lsb_release -c) main" | sudo tee
/etc/apt/sources.list.d/chris-lea.list
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys C7917B12
sudo apt-get update
sudo apt-get install nodejs
curl http://npmjs.org/install.sh | sudo sh

If you'd rather not use Chris' PPA, any system package (Debian or RPM)
named "nodejs" will suffice as an entrypoint for managing npm
packages.

Second, you must install npm packages globally (with the -g flag) in
order for them to be included in blueprints. This typically means
you'll need to set NODE_PATH="/usr/lib/node_modules" to use these
modules.

With that, npm packages will be included in blueprints to be shared
and deployed anywhere.

Merge commit: <https://github.com/devstructure/blueprint/commit/186b9eaa2652a5907ebf39d24316f827e28925c9>

[1] http://nodeknockout.com/
[2] http://npmjs.org/
[3] https://launchpad.net/~chris-lea/+archive/node.js
[4] https://launchpad.net/~chris-lea/+archive/node.js-devel