Remove example files that are no longer relevant
Sort RuboCop configuration
Declare Ruby version dependency in gemspec
Handle introspecting boolean constants
Add unreleased change log items
Make RuboCop ignore rake task definitions

These may be dealt with later.
Update cop names
Auto-correct Style/SymbolProc offenses
Fix LineLength offenses
Clean up RuboCop offenses [merges 'update-rubocop']