Add a Feedback loop parsers

[kruisdraad]

Many receivers, including AOL, Yahoo and Hotmail, offer feedback loops to notify senders when complaints are generated by their users via the "This is Spam/Junk" button.

AbuseIO should be able to parse such notifications

[kruisdraad]

contacted several feeds like AOL to receive messages that we can use as samples

[kruisdraad]

AbuseIO/parser-fbl implemented

another YT task has been issued to implement automatic escalations from info to abuse, and from abuse to escalations so that a single mail will be reported as info and not bother the enduser too much. Only when a threshold is hit you'd want to consider a FBL as abuse.