Fix invalid links in japanese tutorial
translate japanese tutorial for 0.13
Remove needless text from intro
Fix mistranslation
Modify JA translation
add sbt-heroku plugin
Fix to use isSnapshot
Update 03-Howto-Generating-Files.md

fix broken links
built-in repositories. Fixes #42
Adds sbt-pom-reader
rearranged the organization of plugin page.
finish part of 08-library-dependencies
finish 08-Library-dependencies