Add ability to change model results based on topic models

[andrewtavis]

A potential addition to wikirec would be allowing a user to change the recommendations based on the topics. As of now this is only a sketch, but the general idea would be that topic coherences could be returned to the user with the words that define a topic, and then the user could say that they want results that are more in line with a topic by passing percentages a word or n-gram along with a general score. 0.5 could be that topics that include the passed word would not be weighted, with numbers below or above implying that topic importances should be shifted based on the words importance in them.

This would allow a user to express interest in genres, or simply say that results should be more similar to those that are focussed on a similar topic keyword. kwx could be looked to for topic keyword derivation in this case.