Clean up formatting of numbers in gpx export.

Addresses issue #299 and ensures Latitude and Longitude are formatted
correctly as well.

Also orders the elements in the waypoint correctly according to the
schema: <ele> and <time> need to come before <name> and <desc>.

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:9