Link forwarded email to To/CC within email body

[JoshMcCullough]

Feature

When an inbound email is imported, search the email body for forwarded portions of the message. Within each, locate the unique recipients in that each message was sent To (or CC). For each of those unique recipients, link the email to the related contact.

Context

Currently, if I forward an email to our group email that we use for SuiteCRM, the email is not automatically attached to the related contact(s).

Note: I tried to hunt down the linking code and found this, but it's commented out and the referenced handleLinking function does not appear to be in use.

If someone can point me to the code which manages the email -> contact linking, I'll do a PR for this.