Ui tweaks

**Updated Engagement Navbar Icon**
Old
![screen shot 2014-09-15 at 2 18 25 pm](https://cloud.githubusercontent.com/assets/910510/4276589/99c261fa-3d06-11e4-875f-991186a8dbc6.png)

New
![screen shot 2014-09-15 at 2 18 39 pm](https://cloud.githubusercontent.com/assets/910510/4276590/9c80b522-3d06-11e4-9941-6668887f3efb.png)

**Updated Section Heading**
Old
![screen shot 2014-09-15 at 2 33 25 pm](https://cloud.githubusercontent.com/assets/910510/4276616/e8267f7a-3d06-11e4-82e3-ef03c44dacba.png)

New
![screen shot 2014-09-15 at 2 32 58 pm](https://cloud.githubusercontent.com/assets/910510/4276617/eac0d762-3d06-11e4-89b1-138b8845807a.png)

@dsjen @rocha @shnayder @marcotuts