First step of data flow refactoring.

This moves all data source connections into the TrackDataHub.

There are still many things to (re)do here:
- Optimizations about when the listeners are registered
- Optimizations about what data each TrackDataListener is interested in
- When activities are restarting, send new data since they were stopped (instead of doing a full reload)
- Proper double-buffering of Location objects (some listeners are interested in double-buffering all points, while others are only interested in double-buffering sampled points)
- etc.

SignalStrengthSamplerTest/default.properties

@@ -0,0 +1,11 @@
+# This file is automatically generated by Android Tools.
+# Do not modify this file -- YOUR CHANGES WILL BE ERASED!
+#
+# This file must be checked in Version Control Systems.
+#
+# To customize properties used by the Ant build system use,
+# "build.properties", and override values to adapt the script to your
+# project structure.
+
+# Project target.
+target=Google Inc.:Google APIs:11