Implement Jekyll Blog Comments

[haacked]

Following the instructions in https://github.com/damieng/jekyll-blog-comments
to set up haacked.com to use a jekyll+azure based comment system.

I still need to add all the comments and test this out.

TODID

• Move JavaScript to its own file.
• Add a remember me button.

It's hard to look at the changes because there are so many file changes, but this PR contains four commits:

1. The changes to my Jekyll templates. This is the interesting commit!
2. Import all of the comments.
3. This blog post announcing the change.
4. A commit where I update the post to link to the third commit. I can link to it here because updating the PR doesn't create a new commit. I couldn't link to it in the actual blog post because then I'd need to create a fifth commit and so on and so on.