As a user I would like to import npm modules

[julienmoumne]

npm modules offer a convenient way to factor and distribute Hotshell patterns, see hotshell-util as an example.

Downloading npm modules is straightforward using a Node environment.

However, Hotshell does not require Node and should remain, at runtime, dependency free.

This ticket is about finding a way to make Hotshell interpret a package.json file and download the required dependencies.

One idea would be to integrate the npm lib using Otto.