Adding shoutbox feature for user pages and user's dashboard

@cgruppioni @chukdisc

I also know that I'm using _path for many link_tos, but those are all placeholders until I actually use them. Also, wouldn't mind tips on what I should be doing with my divs, classes and ids + css.
`owner` seems like a bad name for this. when I think owner, I think the person who sent it. can you think of a better name?