Updated help output.

The --node_version help has been updated to show v0.10.22 as the default. Also
changed the way the default is set and updated the version that is output to
use the version in package.json.
Merge pull request #43 from onmodulus/option-update

Updated help output.
Merge branch 'master' into develop
Modified API for --tarball support.
Bumped version to 0.4.0.