Allow user to define background location update frequency

[anzhieta]

Since Location Buzz requires relatively high accuracy but we also don't want to leech too much power in the background, it might be useful to allow the user to set the accuracy and update interval themselves to suit their own usage

[Kapoor-uh]

One way to proceed is to add a new condition in code along with BGACCURATE, which decides polling interval on basis of buzz place radius. If radius of Buzz place is too high we can set polling interval large and if radius is small we can set polling interval small.