Rewrite get_latest_answers + Fix #36

Fix issue #36 + *readable* variables names

added helper functions:
* check_log_types
* and is_<log_activity>_log(entry)
http://stackoverflow.com/questions/12339323/beautifulsoup-findall-find-all/12339416#12339416
http://www.crummy.com/software/BeautifulSoup/bs4/doc/#method-names