MessageTree.scala walk directions reversed

[mhluska]

See here @crockpotveggies .

We have:

case Right => this.left
case Left => this.right

Shouldn't it actually be:

 case Left => this.left
 case Right => this.right

Also, a couple things are broken:

• I'm having issues with the match's name. In FunMessages.scala it ends up as a blank string. I can submit a PR
• The runLengthConcat function in MessageUtil.scala seems to be broken. It concatenates all messages into one, not just repeated ones. Then there is only one sentiment and the matches get endlessly repeating messages from me

Also, it would be cool to link to a guide on obtaining the Facebook oauth token. I had to use a proxy since copy/pasting the URL doesn't work anymore.