[#53420683] Updates the "change group colors and logo" page. Removes the "change group logo page".

Requires https://github.com/AllPlayers/brochure.allplayers.com/pull/159.

A fair amount of the guide for changing the group's logo was already in the guide for changing the group's colors. There wasn't a compelling reason to have two posts with very similar content so I merged the two together since they are so similar.


![allplayers com](https://f.cloud.github.com/assets/2251119/1657302/e15cfca0-5b7f-11e3-915e-d51d5dd3987a.jpg)


![allplayers com 2](https://f.cloud.github.com/assets/2251119/1657300/e14a8e26-5b7f-11e3-9b6b-99d8433e27d1.jpg)


![allplayers com 3](https://f.cloud.github.com/assets/2251119/1657301/e153c8c4-5b7f-11e3-83ac-851c586c1e8a.jpg)