Migration belonging to previous commit.
Added newest version of article to versions view
Added links to versions list, implemented display of article versions.
Changed stylesheet for links appearing in .muted sections.
Refactored article preview in categories to use a template.
Added options to category form and made it show up in category edit requests.
Changed application.js to no longer require mercury as it is only needed for signed in users.
Implemented update functionality for categories-
Refactored user error messages partial to be used for generic objects and put it to use for categories form.
Fixed typo in login reirect flash
Added preliminary introduction text for apha testing to the home page.
Increased font size for category headings.