catch requests.ConnectionError as HTTPError
introducing NumberInNameError
Replacing ''' with """ in all modules. (PEP 257 recommendation)
important bug fix: let BS decide about encoding (instead of requests)

example url: http://socialhistory.ihcs.ac.ir/article_319_84.html
It appears that Beautiful Soup has a better encoding detection algorithm.
d['number'] --> d['issue']
d['nubmer'] --> d['issue'], +issn
added a few function to detect journal citations

find_journal(bs)
find_issn(bs)
find_volume(bs)
find_issue(bs)
find_pages(bs)
update