Add struct instance name to the plot legend.

It was hard to read when two different structs have elements with the
same name in them.

Change-Id: I588d512cb297d6743ff5c51df4b39c58c49fbf3f
diff --git a/frc971/analysis/analysis.py b/frc971/analysis/analysis.py
index 66c5056..8152607 100755
--- a/frc971/analysis/analysis.py
+++ b/frc971/analysis/analysis.py
@@ -70,7 +70,8 @@
     """
     for key in self.signal:
       value = self.signal[key]
-      pylab.plot(value.time, value.data, label=key[0] + ' ' + '.'.join(key[2]))
+      pylab.plot(value.time, value.data, label=key[0] + ' ' + key[1] + '.' + \
+          '.'.join(key[2]))
     pylab.legend()
     pylab.show()