_s: Move away from using <article> for content that is not syndicated.
_s: Let's not change .entry-date.
_s: Let's keep the `.entry-` namespace for page post types.
_s: Let's keep the `.entry-` namespace for attachment post types.
Update mention of tweaks.php in README.md

I first thought my download was broken, but I believe this file is no longer in use.
Updated with mention of extras.php instead
Added strip_tags when get_the_title is used for title attribute in image.php

Aaddresses _s issue 184 - https://github.com/Automattic/_s/issues/184
Skip printing categories widget in 404 template if there's only one category

Addresses issue 183 - https://github.com/Automattic/_s/issues/183
_s: Add a Post Format Archives heading to archive.php. Props @sixhours,
@philiparthurmoore. Fixes #95.
Merge pull request #188 from slobodan/issue-184

Added strip_tags when get_the_title is used in title attribute in image.php. Fixes #188.
_s: Use the_title_attrinute() when we don't need to specify a post.
See #188, closes #184.
Merge pull request #180 from pierrepavlov/patch-1

Update mention of tweaks.php in README.md
_s: /inc/etras.php is active by default.
Corrected if statement formatting
_s: Remove vendor prefixes on box-shadow and some legacy IE6/7
adjustments. Props @SeamlessThemes. Fixes #176.
Merge pull request #189 from slobodan/issue-183

Skip printing categories widget in 404 template if there's only one category.
_s: Minor updates to categories widget. Closes #183.
_s: Revert partial heading change.
_s: Simplify the way we do responsive images. Props @philiparthurmoore.
Fixes #120.
Update stylesheet to include proper copyright and license attribution in style.css. Fixes #10 and also reverts the changes that were made in 06463db11dd44908c9ba2d5aef2ea70a97e142f7, since we can now use this copyright notice to find out which themes are based on Underscores.