Multiple changes

[oxivanisher]

Hey :)

I really like your project and made some changes:

• More documentation on setup/configuration (Resolves Documentation: Enable SPI #4)
• Lots of changes to make the PEP8 linter happy
• Calendar now supports multiple calendars and can ignore explicit entries
• More internationalization by supporting 12h/24h display and other charsets (i.e. to display öäü)
• Google todo shows now all lists where the name contains todo (case insensitive). The todo list id was hard-coded and did not work for other people.
• Optimized string handling (i.e. more Unicode compatibility)
• Some preparation for python 3 support (not tested on python 3 yet)
• The quasi default for line endings is Unix style. Because of this, all files are marked as changed. :(
• Adding screen saver to prevent burn in (which IS happening without it) https://www.waveshare.com/wiki/E-Paper_Shield