Convert from ERB to slim

refs: http://stackoverflow.com/questions/10347572/convert-erb-template-to-slim
      http://www.22ideastreet.com/debug/converting-erb-to-slim/
add slim-rails
fix application.html.slim
fixing missing part...
fix hatena bookmark link
remove misterious slash...
remove misterious slash
fix _snippet.html.slim
fixed syntax error
space was removed when convert
remove slash
add break line

refs: https://github.com/iiirc/iiirc/pull/88#commitcomment-3246451
Merge pull request #88 from iiirc/convert-erb-to-slim

Convert erb to slim