More build options

Handle build process with node-webkit-builder.

It can now build for all platforms. Even linux. See readme.

Will need to update dependency version when they publish a working npm
package. Probably in a few days. It now links directly to the git
repository, since published version (0.0.1) doesn't work properly.

There's a PR to node-webkit-builder to support windows ico setting. When
that gets merged, it will automatically set the Cuevana icon.

Related https://github.com/Cuevana/storm/pull/46 https://github.com/Cuevana/storm/pull/61