Fixes issue #2366
Merge pull request #2368 from xyz/2-1-stable

Fixes issue #2366
Update changelog with proper release date and branch comparison link.
Add note to changelog about #2368.
Remove '_content' from section id

The default Home page and the CSS expect #body and #side_body. To ensure the styling is applied correctly to the About page we need to remove '_content' from the section id.
Merge pull request #2372 from dwayne/patch-1

Remove '_content' from section id
Mention that Refinery CMS is not compatible with Rails 4 and provide a
workaround in the Getting Started guide.
Update Getting Started guide.

* Change version from 2.0.0 to 2.1.0
* Remove tip about Ruby 1.9.1 because lowest acceptable version is 1.9.3
* Remove RubyGems link because it comes bundled with 1.9.3
Bump selenium-webdriver dependency version.
Show Travis build status icon only for 2-1-stable branch.