Add inspection for missing http.Response.Body.Close()

[dlsniper]

The IDE should try to find out if Body.Close() is ever called on a http.Response and if not display a warning about leaking this.

• http://engineering.rainchasers.com/golang/2015/03/03/memory-leak-missing-body-close.html
• http://devs.cloudimmunity.com/gotchas-and-common-mistakes-in-go-golang/index.html#close_http_resp_body
• https://groups.google.com/forum/#!topic/golang-nuts/ZMfxtWhgVfU

[ignatov]

Please clarify the issue.

[dlsniper]

I've updated the issue description with a few useful / related links.
The idea is that if one doesn't close Response.Body then that piece of memory will linger in memory for the whole execution time. Thus, when this happens in an long running program it will lead to memory leaks and eventually crash the program.