Clean the value functions

[ncsilvaa]

It's time to clean (making all copies as necessary) the value functions.

• The correct version of OurMethod should become WSPB (the other one should be for the new repo made for the article)
• What is the difference between Entropy and Entropy0? I'm not sure if it is the best name for this method.

Think about the possibility of grouping these value functions into subfolders (like recommendation classes - I can help in this division).

[ncsilvaa]

I'm not sure if we should keep other recommendation algorithms in this repo (those in mf or recommenders).

[heitor57]

Thanks for you contribution @ncsilvaa! Filtering the things you mentioned these are the things we are going to do:

• [x] Change OurMethod2 to WSPB @heitor57
• [x] Create categories in the documentation of value functions classifying models according to they common characteristics to guide users, tags can also be used @thiagodks
• [x] Transform recommenders in a private module @heitor57
• [x] Add docstrings in Entropy0 with reference to the Active Learning (these can be made to others methods too, like HELF) @thiagodks

So, Entropy0 is a literature strategy, this is the actual name of the method (see "A survey of active learning in collaborative filtering recommender systems" or "C. Boutilier, R.S. Zemel, B. Marlin, Active collaborative filtering").

About the matrix factorization, they are important to be part of the package. Implemented literature models use them and maybe others want to use them in a new method, modify, etc.