update htmldiff
added __init.py__
change submodule url to https
add links to python regex docs and testing tool
readme update
deleted TODO.md
add new line in output after every site
print debug info on not deleting any old items
refactoring to move some methods to functions.py to use them in generate_rss and site_check
add method is_content_different
make use of new method is_content_different, and rely on the regex explaining the content