say good bye to Ruby 1.8*, 1.9.1, 1.9.2.
and hello 1.9.3.
support Ruby 2.0.0
support Ruby 2.1.x
change license to new Ruby's (BSD + Matz)
support trunk, aka Ruby 2.2
refactoring: reorder
update document
Merge pull request #1 from tadd/support_ruby_2.2

Support Ruby 2.2