Move attachments to after govspeak help

So that if there is a very long list of attachments you can still get at
the help. Also moved the add new attachment button to the top of the
attachments list so you can add a new attachment without having to
scroll all the way to the bottom.
Merge pull request #63 from alphagov/move-attachments

Move attachments to after govspeak help

https://www.pivotaltracker.com/story/show/67980148