Use whole/fractional timestamps in the whole chain. This prevents loss

of precision when setting time to UTC.

lib/slicer_impl.h

@@ -38,6 +38,7 @@ private:
     int d_chip_rate;
     int d_samples_per_chip;
     int d_samples_per_symbol;
+    gr::tag_t d_timestamp;
     gr::msg_queue::sptr d_queue;
     std::ostringstream d_payload;