Release 4.17: Add rudimentary caching decorator for functions

Release 4.16.1: More ANSI to HTML improvements (style reset)

Release 4.16: Lots of HTML to ANSI improvements!

Release 4.15.1: Decode entities in HTML to ANSI conversion

Release 4.15: HTML rendering on the terminal 😁

Version bumps considered useful 😇

Release 4.13: Support for italic text rendering on the terminal

Release 4.12.1: Fixes for `humanfriendly --demo' on Python 3 (fixes x…

…olox#28)

Release 4.12: Make format_timespan() accept timedelta objects

Release 4.11: Add a changelog (fixes xolox#23)