Add Ppl::Format::Table#disable_colors! for turning off color
Add Ppl::Format::AddressBook::Nicknames#disable_colors!
Add --no-color to ppl nick's input parser
Make Ppl::Command::Attribute disable list output color if asked to do so
Remove sed from the completion functions and replace with --no-color flag
Merge branch 'nocolor'
Version 1.20.0