Merge pull request #1 from jollychang/reset_iPhone_Simulator

I'm sorry I didn't reply to your pull request. Thank you very much for your commits!
Merge pull request #2 from jollychang/master

add reset_iphone_simulator and support extend javascript
update README
add language refernce
fix title
Merge pull request #3 from jollychang/master

change default README as English.
Update README_jp.md
update README_jp.md again..
fix extend_javascript_path is empty