Remove In App Purchases listing on Play Store

On the Play Store, the app details show 'In-app purchases'.

I believe it's linked to the following line in the AndroidManifest.xml file in android/client/ and android/clientbeta

```
<uses-permission android:name="com.android.vending.BILLING" />
```
![device-2013-12-17-214800 copy](https://f.cloud.github.com/assets/307943/1768613/71baca66-6765-11e3-86ea-3d718033ef16.png)

Should these lines be removed to avoid any confusion? It's always best practice to require only services you need in android.