Display visible GPS satellites

This is a suggestion for a partly fix of #973. I put the "/" to the strings.xml for RTL compatibility.
![gps](https://cloud.githubusercontent.com/assets/3845150/4710017/c9f7c3e2-58a4-11e4-93d0-e31f8c27b999.png)

Android keeps on trying to calculate a GPS position even with 3 Satellites and less.
This variable is not about the first fix, the first fix occurs with more GPS satellites.
Once Android has a fix it is able to keep the connection to the satellites.

I don't think this has ever caused issues before, has it?