Add Bundler installation instructions to README

- plus minor spelling corrections
Merge pull request #13 from dloss/bundler

Add Bundler installation instructions to README
Add missing migration from 3297c389a1d4976f671
Make a partial from the navbar

- move navbar to a partial
- make 'new snippet' to plus icon
- make 'help' to question-sign icon
Truncate posts on the index page
Update bundle
Update rails to fix security issues
The bug is not here
Prettify error default error messages
Add parent child association to Post

To have versioning in graveio we need a parent child association
between posts. If a Post is updated, its not updateing it but
rather creates a new post as a child of the former one.

Next step: diffing between posts.
Only show newest children posts in index
Revert "The bug is not here"

Only a show case for http://munich.rubyshift.org

This reverts commit 6a35ff3f6aef133b0af3173ddaa4243a926af23c.

Conflicts:

	app/models/post.rb
Two posts can now be diffed and shown to view

We use Diffy now to show a diff between a parent and a child.

We still miss the link and a possibility two show the
diff between selectable posts.
Add diff buttons to view

and missing file
Add diff buttons to view

and missing file
Add diff buttons to view

and missing file
Merge branch 'diff'
Post entries didn't show their comments

there is a collect function for posts, which show
the post comments and of all the parent posts. The function
didn't show the own comment.
use pygments.rb as highlighter
add content_type label to form