Added path in url.

Page#dir was returning the wrong dir ('/') for pages in directories.
Scaffold site, based on @mojombo's site (with permission).
Added the NewCommand class
Added the site_template files to the gemspec manifest.
Added command to primary binary.
Using modularized commands (Jekyll::Commands) as per @tombell's latest PR merge
removed related posts segment of scaffold site.
Added newline to New command for stylistic congruence.
Move post scaffold content to a separate method.
Added very basic code snippet example to sample post
Using .erb file for the new post
Fix pretty url style paths.

Ignore the basename if the page is an index page, preserve it if it's just an
html page and use the full path in every other case.
Typos in sample post.
We don't need YAML in the new command.
Update Readme to link to the Plugins wiki page
Adds excerpt to posts
Remove duplication when generating list of entries to process

Posts and Drafts share the same logic to get the list of files to
process into objects when generating the site. Factor this logic into
its own method and use it when reading posts and reading drafts.
Remove duplication when aggregating post information
Added mime.types file from Apache SVN repo.
Jekyll::Commands::Serve reads in mime.types file.