added preliminary page layout for Articles#new
added section model and relations
added basic page layout for Articles#new
added stub for article creation to controller.
removed presence validation for article.body
changed validations for articles to allow for saving of new articles by submitting the form
changed views to accomodate new article model with sections
adjust populate tasks and article creation in specs to use sections instead of article.body
authorization for creation of articles
fix assignment in sample data creation to hopefully satisfy herokus ruby version
changed categories view to hide new article link from users not signed in
added tests for all pages header layout
add new category link to header when signed in
Added functionality to add categories.
changed database to allow for saved articles that are not displayed
Changed article, category models to incorporate display attribute.
Tried some stuff in the articles model.
Merge branch 'master' into mercury-switch-after-revert