For template site, convert #post to .post.
Merge pull request #1170 from mojombo/remove-ids-from-site-template

For template site, convert #post to .post. Fixes #1161.
Update history to reflect merge of #1170.
Add a Pro Tip to docs about front matter variables being optional
Merge pull request #1147 from beeeswax/frontmatter-nil

Add a Pro Tip to docs about front matter variables being optional
Update history to reflect merge of #1147.
Added a --blank command which scaffolds empty files.
New leaving empty layouts / posts dirs and empty index.html.
The start of something cucumber.
Broken test committed. Can't find proper directories.