Mark own shouts

[Radiergummi]

This adds an ownShout class to the shout container, so you can style own shouts differently.
I used it to create this (totally not facebook inspired) chat:

[Schamper]

Makes sense to have a class like that (nice design!).

I've recently started a very big refactor (that will actually work towards #53), I'll merge it for now and I'll be sure to add it in the new version. I might change the class name but I guess I'll ping you by that time.

[Radiergummi]

I used self as a class name for my board (as seen in nodebbs chat templates), but thought ownShout might be a little more explainatory ;).
When you are done rewriting the thing, I could throw in the styles as well.