Add location API

[blochberger]

Jain et al. [1] proposed a location API that nudges developers to use location data in a more privacy-friendly manner. We should definitely implement this to make this accessible to more developers.

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1. S. Jain and J. Lindqvist, Should I Protect You? Understanding Developers' Behavior to Privacy-preserving APIs in Workshop on Usable Security (USEC '14), 23 February, San Diego, CA, USA, 2014