Initial commit with bundle support
Add Guardfile for auto-compile
Basically works.

1. Adopt http://www.bootply.com/render/96266 theme.
2. Adopt h5bp html template as the default layout.
3. Add some meta data to site.
4. Add favicon and gravatar.
Add a pandoc_system filter.

This filter just call pandoc directly due to some limitations of nanoc
and pandoc-ruby, see stackoverflow:
http://stackoverflow.com/questions/14646741/nanoc-how-can-i-pass-options-to-pandoc-ruby
for details.