Validate config helper input
Configure method takes username/password

When using the configuration helper, the API key is now either
retrieved or generated directly from the API using a username
and password.
SSH pubkey support on Linode create
Provide IPs for JSON list and show
NodeBalancer Support

- NodeBalancer support (create, rename, throttle, list, show, and delete).
- NodeBalancer port/config support (config-create, config-update, config-delete, config-list, config-show).
- NodeBalancer node support (node-create, node-update, node-delete, node-list, node-show).
- Some documentation updates
Fix object listing bug
Minor cleanups
Release 0.3.0
Release 0.3.1