I added RSS feeds for each blog category.

I created the rss.xml layout file and the rss_post.xml template file. I
created RSS feeds for each blog category. I revised the category.html
template to include a link to the category RSS feed.
I fixed the post layout and featured article layout on the homepage.

I changed the post.html layout to match the other pages with the blog's
category tree in the left column. I changed how the featured article
rendered in the homepage to make the rendering more consistent with the
other post layout.
I removed the excerpt paragraphs from all of the posts.

I removed the first paragraph from all of the posts. I added it to use
the new excerpt support in Jekyll, but I was expecting the first
paragraph to not get displayed in the page. This wasn't happening. Not
sure if it's a Jekyll bug or my misunderstanding.
Merge branch 'release/1.0.0' into develop