add bin to .gitignore.
set project encoding.
add Rhino to build path from sample dir.
remove SVN metadata.
Merge pull request #5 from taichi/cleanup

リポジトリ内を最低限整理しました。
add license
Update README.md
add build script.
change encoding from Shift_JIS to UTF-8
adjust project layout.
add developers manual.
fix encoding problem for javadoc task.
remove javadocs.
remove eclipse project files.
add jar task.
Merge pull request #6 from taichi/add_build_script

Gradleによるビルド環境を整えました。
Update README.md