JOINDIN-475 Use Forwarded and X-Forwarded-For headers in Akismet check

[Adam Dear]

Hi all,

I'm working on this issue and have a first go at it complete. I would very much like some feedback on what I've done before I do  pull request.

The work I've done can be found at https://github.com/adear11/joindin-api/tree/JOINDIN-475

Thanks for the feedback.

-Adam