update tutorial navigation

1. remove translator factory
2. update manual link
3. move navigation inside class = "nav navbar-nav"
4. remove divider "/" , no need.

**Old**
![nav-old](https://f.cloud.github.com/assets/459648/1899346/f2eaf132-7c38-11e3-8833-04592322a2ba.png)

**New**
![nav-updated](https://f.cloud.github.com/assets/459648/1899352/0506bd92-7c39-11e3-9985-352ddce8eb0e.png)