Reverted changes to << - go back to returning self as per discussion on mailing list.
Reverted changes to << - go back to returning self as per discussion on mailing list.

xml4r/libxml-ruby,increments/libxml-ruby,sferik/libxml-ruby,sferik/libxml-ruby,xml4r/libxml-ruby,increments/libxml-ruby,sferik/libxml-ruby,xml4r/libxml-ruby,increments/libxml-ruby,sferik/libxml-ruby,sferik/libxml-ruby,sferik/libxml-ruby