• Apply PR/171 (fixes issue/109) @perlpunk++
  
• No more "used only once" warnings for $YAML::Indent etc.
  
• Apply PR/170 (fixes issue/131) hiratara@cpan.org++
  
• Empty mapping value at the end resolves to null (was becoming empty
  string)
  
• Apply PR/169 (PR/119) patrick.allen.higgins@gmail.com++
  
• Output key in warning when duplicate key was found
  
• Apply PR/157 and PR/168 (@lameventanas++ @perlpunk++)
  
• Allow reading and writing to IO::Handle