Various tweaks and fixes

[pythonian4000]

These should probably be separate pull requests, but oh well :grin:

• Kindle conversion profiles have been updated to include Kindle 4 and 5
• Default output dir for conversion is images for Kindle 5
• Code now works if socks module is not installed, and only fails if user specifies a proxy
• Bugfix: --device option works now
• MangaHere tweaks:
  • Fractional chapter numbers are supported
  • Manga search will wait 5 seconds if MangaHere asks for it
• Batoto support pulled in from another fork (requires BeautifulSoup 4)
  • Set up so that if the user does not have BS4 installed, Batoto is not provided as an option

I had also tweaked MangaHere to ignore the "next chapter" link in ongoing manga (as it doesn't exist), but your recent update negated it (and so I overwrote my tweak in my recent merge).

[pythonian4000]

Creating a new pull request with a specific branch.