Fix nav to make statistics highlight the correct nav item

Some statistics are actually publications so we have to extend the check to include documents of statistic sub types which are actually publications.

Before
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![screen shot 2014-03-17 at 17 41 28](https://f.cloud.github.com/assets/215/2439323/78fc3eea-adfb-11e3-9fd1-290d78057435.png)

After
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![screen shot 2014-03-17 at 17 41 49](https://f.cloud.github.com/assets/215/2439329/8079e8ac-adfb-11e3-932c-55d8160588cc.png)