Update mecab-ko-dic to 1.6.1-20140814

Updated mecab-ko-dic to 1.6.1-20140814. Also removed the caveats editing config manually and added a shell command to do it automatically instead.
```ruby
unless IO.readlines("#{etc}/mecabrc").any? { |line| line.include?("dicdir") }
  inreplace "#{etc}/mecabrc", /dicdir = .+/, "dicdir = #{opt_prefix}"
end
```

Maybe?