Fixes DEVELOPER-686

Using a new transformer to look at links and add the "external-link" css
class if it is linking to something off the `site.base_url` domain.

Fixing false positive results for external links

Better fix for searching for non text children
Adding (or removing) external link icons

Buzz and projects, also fixing up the display on the right bars.

More fixes for DEVELOPER-686

* Removed some explicit external link icons
* Fixing up the product get started buzz icons
* Removing extra space from product get involved link
DEVELOPER-800 remove duplicate title description
DEVELOPER-801 use CDN path for sprites
New project icon sprites. Fixes DEVELOPER-763

project icons

Project Icon sprites. Fixes DEVELOPER-763

project icon stylesheets
Updating FUSE get started to work with OS selector
DEVELOPER-802 Added site.base_url into the links
Fixed ordered list bullets not lining up. DEVELOPER-798
Only install rake if needed
Merge pull request #352 from LightGuard/DEVELOPER-686

Fixes DEVELOPER-686
Update cdn.yml
Merge pull request #374 from pmuir/DEVELOPER-800

DEVELOPER-800 remove duplicate title description
Merge pull request #376 from pmuir/DEVELOPER-801

Developer 801
Merge pull request #378 from wesbos/DEVELOPER-797

Updating FUSE get started to work with OS selector
Merge pull request #380 from Dantheman720/DEVELOPER-802

DEVELOPER-802 Added site.base_url into the links
Merge pull request #383 from pmuir/only_install_rake_if_needed

Only install rake if needed
Update cdn.yml
Merge pull request #382 from wesbos/DEVELOPER-798

Fixed ordered list bullets not lining up. DEVELOPER-798
Update cdn.yml
Update cdn.yml