Display format on post-show page

ub-15

Now the post-show page shows HTML formatting, rather than
just the HTML tags. The post-index page shows first 20 characters
including HTML tags. Having trouble combining encodeAsRaw() with
the text abbreviation.
Merge branch 'develop' of ssh://github.com/osu-mist/ublog into feature/ub-15-improve-post-display
Show last-updated

ub-15

In the Show view for posts, now displays the date of last update. The main CSS
has also been modified so that the green background extends to the bottom
of the screen, regardless of the size of the page body content.
Improve display

ub-15

Using HTML 5 for the input forms for new user and new post, improve the
 home page, extend the green background to the bottom of the page.
Merge pull request #8 from osu-mist/feature/ub-15-improve-post-display

Feature/ub 15 improve post display