Updated changelog for new features going in with version 0.9
Adding documentation for the new site-wide HTML header feature
Adding a note about the new configuration validation
Updating the changelog for new functionality
#14 Added documentation about overriding the layout template
Update README.md with information about relative web addresses
Add example for site-specific HTML Header include
Update CSS and js
Merge pull request #17 from tpwalke2/development

Development branch merge