Update Mroonga's version 4.00 to 4.02.
Merge pull request #11 from yoku0825/mroonga-4.00_to_mroonga-4.02

Update Mroonga's version 4.00 to 4.02.
Add 5.5.38, 5.6.19

http://dev.mysql.com/doc/relnotes/mysql/5.5/en/news-5-5-38.html
http://dev.mysql.com/doc/relnotes/mysql/5.6/en/news-5-6-19.html