added string resource for distance-based filter
updated activity_filter layout to add distance-based filter options
EventsFilter: added non-serializing currentLocation member variable with setters so that it can be used for distance-based filtering
EventFilters: add a distance-based filtering clause to the query if the currentLocation is set and maxDistance is greater than zero
MapDemoActivity: when applying filters to queries, update the filters object with the current location, if available
FilterActivity: populate distance-based filter spinner and load and store setting in filters object
Merge branch 'master' of github.com:hdahme/IterApp
MapDemoActivity: don't try to sort an empty list of LocationUpdates if we get one back from Parse, since sorting empty lists seems to cause an infinite loop and/or crash