Create mf_helpers.py

added function ```just_urls_plz``` to get a list of urls only.
Update mf_helpers.py
Update microformats2.py

updated to get just the urls even when embedded microformats exist
Create article_with_in_reply_to.mf2.html

for testing ```u-in-reply-to``` parsing. both normal in-reply-to and embedded in h-cite included.
Update microformats2.py

moved getting bare urls here. See function ```get_string_urls```.
Delete mf_helpers.py

moved to microformat2.py
Update microformats2.py
Merge pull request #5 from kartikprabhu/master

improved in_reply_to parsing