Bump Rack version to leverage security fixes.
Remove cruft from Gemfile.lock since rspec is no longer specified in the Gemfile.
Simplifying clean task.

* Make it less needlessly noisy (no need to enumerate all files when doing rm_rf).
* Explicitly nuking screen.css is superflous as `compass clean` will do this for us.
* Make task description more accurate about what's happening.
* Make task feedback less redundant (details of what was removed are right above it).
Allow .md for markdown files.
Some Jekyll plugins confuse Compass by mucking around with the CWD.

This keeps things behaving sanely in such cases.
Grand whitespace cleanup.
Removal of apparently unreferenced, dangling method.

(A search of the code reveals no reference to 'parse_category'...)
An update of rretsiem's pull request, for 2.1.
Make it possible to disable the comments section entirely without having to muck with theme files.
Merge pull request #1055 from MrJoy/allow_short_markdown_extension_redux

Allow .md for markdown files.
Merge pull request #1059 from MrJoy/compass_rigor

Compass rigor.
Merge pull request #1058 from MrJoy/grand_whitespace_cleanup

Grand whitespace cleanup.
Merge pull request #1056 from MrJoy/dead_code_removal

Removal of apparently unreferenced, dangling method.
Merge pull request #1064 from MrJoy/fb_async_21

Make FB JS load synchronously so it doesn't block page rendering.
Merge pull request #1041 from MrJoy/cleanup_gemfile_lock

Remove cruft from Gemfile.lock since rspec is no longer specified in the Gemfile.
Merge pull request #1050 from MrJoy/update_rack

Bump Rack version to leverage security fixes.
Adding a default for comment disabling.
Merge pull request #1048 from MrJoy/simplify_clean

Simplifying clean task.
Merge pull request #1066 from MrJoy/enable_disabling_comments

Make it possible to disable the comments section entirely without having to muck with theme files.
Testing against Ruby 2.0. Closes #1075.