Track Frequently Asked Question in the Answer Tracker

This specification is about allowing tracking 'FAQ' document in the Answer Tracker. FAQ document are meant to capture documentation around a particular common question. They are similar in scope to what other systems call Knowledge Base Entry or Technical Information Document

The structured discussion that follows a question isn't the most suited format to explain variations to a question. The discussion might contain elements needed to pinpoint the problem, but that in the end aren't relevant to the answer. FAQ documents are meant to be more suited to longer explanation.

FAQ are also meant to represent a canonical answer to a question. It will be the place to consolidate knowledge spread around forums, wiki pages, mailing list and various other places.

Initial feature set will include:
- Answer contacts will be able to create FAQ document from an existing question.
- Searching for FAQ documents when asking a new question.
- Replying to a question with a link to an existing FAQ document.
- Content of the FAQ can be stored in Launchpad or at an external resource.