First version of check_activity + new helpers + merged follows and want_anwers

check_activity is now given the entire entry and make use of three new helper functions:

* is_author(link, baseurl): check if the user is author of the answer or only upvoted it.
* is_review(link): check if the user is asking for a review
* want_answers(description): check if the user is "wanting an answer" i.e "follow a question".

I decided to split the BeautifulSoup casting in two parts to preserve variable immutability / clarity.

The exception checking in my helpers function is a bit messy, I will need to double check/test that. 

I merged follows and want_answers because there is no way to distinguish them from one another and Quora decided to strip users from their ownerships of questions.