Improving the importing of old blog posts, save it as HTML.

- Let the creation of the posts.json to the build/blog.js script.
- Fix lib/compile-md backward compatibility when the path argument was
  not given
Import old blog posts.
Make the twitter API usage optional.

If it's not there, just ignore it.
Merge pull request #101 from arian/optional-twitter

Make the twitter API usage optional.
Merge pull request #100 from arian/blog-posts

Import old blog posts.
add older version for More's docs
after review improvments
Merge pull request #97 from SergioCrisostomo/add-older-docs

add older version for More's docs
Remove wrapup-webbuilder dependency, not used anymore
Merge pull request #102 from arian/remove-webbuilder

Remove wrapup-webbuilder dependency, not used anymore
add books
refactor builder layout

refactor builder layout to have same theme/layout as Core/More,
depending on which builder is being navigated.
make guides layout same in Core and More
add empty line
use alt tags

use alt tags in image
open books in current page
Merge pull request #103 from SergioCrisostomo/use-same-layout-for-builder

refactor builder layout
Merge pull request #105 from SergioCrisostomo/guides-style-fix

make guides layout same in Core and More
add better snippet to More's overview

add Table constructor example to More's overview
replace "average" by "JSONP"
Merge pull request #104 from SergioCrisostomo/add-books

add books