Set a User-Agent for HTTP requests from :elinks
Set a User-Agent for HTTP requests from :elinks

Goals:
* The default “Ruby” User-Agent is blocked everywhere so replace it.
* Include “Mozilla/5.0” to pass through a lot of blocking filters and because it’s required due to the legacy of the web.
* Include Nanoc software name and version to identify the software making the request.
* Describe the purpose of the request to help webmasters make informed blocking decisions.
nanoc/nanoc