Find sim. questions

[irbowen]

We should download and index all questions, and then create a system where new questions will be added to the index. When a new question is added, it should first be compare to all other questions in the index. If it is very similar, and that question has been answered by an instructor, our bot should reply to it right away by linking to that question.

[irbowen]

Follow up - need to determine what we are going to use for the index.
We could use lucene for keyword search, or store posts in postgres and use full text search.
Other ideas?