Merge pull request #14 from kiawin/master

Updated HTML class references
Change URL_BASE to mangafox.me to match new domain name
Fix bug where manga names with spaces were not recognized properly
Remove unecessary creation of temporary page.html file
Fix pep8 and pylint errors
Fix quotes and print statements to be more Pythonic
Fix bug where the wrong chapter would download

Previously, the download_manga() function would assume that the list of
chapters in a manga would have a one-to-one correspondence with their
index in the chapter list. This is not the case if a manga has chapters
with decimals or a chapter 0 or some other nonstandard numbering. The
get_chapter_urls() code has been rewritten to use a dictionary instead of
a list so that the download_manga() function no longer relies on any
one-to-one correspondence between chapter number and index in the list
of chapters.
Fix for Issue #1 where ranges download incorrectly
Simplify make_cbz(), download_urls(), and get_page_numbers() functions
Merge branch 'indexfix' to fix downloading the wrong chapter number
Removed no_warning url parameter for mature mangas

MangaFox no longer uses the no_warning url parameter so it no longer
needs to be in the code
Fix escaping issue where mangas would not be found

Previously, the script only replaced spaces with underscores in the
manga name to get the url fragment for the manga. This led to a bug with
reproducible with the manga "To Love-Ru Darkness". The manga would not
be found because the hyphen was not being converted into an underscore.
Added support for BeautifulSoup 4
Updated README.md to remove caveats
Fix Issue #5 where script dies on licensed manga
Fix quotes and simplified get_page_numbers()
Fix bug where script dies on pages with no image
Die before creating chapter_urls dict if there are no chapter links
Add support for "manga_name" alongside "Manga Name"

Mangas can be inputted in the url format (e.g, nana_to_kaoru) as well as
the format displayed on the page (e.g, Nana to Kaoru). Fix for bug where
the script would die with an IndexError when the manga name was inputted
in the url format because the manga name would not be filtered out of
the link text (the key/index for the chapter_urls dictionary) for each
chapter link.
Display error message for non-existent chapters

Checking whether chapter_number is in chapter_urls before passing
possibly non-existent key to chapter_urls. If the chapter_number is not
an existing key in chapter_urls, display an error message instead of
crashing.