Define NODE_ENV based on the configuration and define NODE_PATH when
either npm.install or npm.env are true. The latter behavior is
necessary for final stages of multi-stage builds where npm modules are
not installed but the application requires node-related environment
variables to run.
Rename npm module/config to node
Renamed npm yaml entry to node and NpmConfig to NodeConfig.
Since we're dealing with general node builds and configuration, this
seems to make more sense.