Merge branch 'release/0.6.3' into develop
add burst detection API reference draft
fix constraint
fix constraint
fix config description
go with the latest IDL spec
fix order of API references
fix typo
add English version
Merge pull request #167 from jubatus/add-burst

add burst detection API reference draft
fix format (refs #167)
fix typo (refs #167)
fix title of tutorials (fix #168)
bump version
Merge branch 'release/0.6.4'