Add the flush calls back to statedatareporter properly protected by try-except.

wrappers/python/simtk/openmm/app/statedatareporter.py

@@ -117,6 +117,10 @@ class StateDataReporter(object):
             self._initializeConstants(simulation)
             headers = self._constructHeaders()
             print >>self._out, '#"%s"' % ('"'+self._separator+'"').join(headers)
+            try:
+                self._out.flush()
+            except AttributeError:
+                pass
             self._hasInitialized = True
 
         # Check for errors.
@@ -127,6 +131,10 @@ class StateDataReporter(object):
 
         # Write the values.
         print >>self._out, self._separator.join(str(v) for v in values)
+        try:
+            self._out.flush()
+        except AttributeError:
+            pass
 
     def _constructReportValues(self, simulation, state):
         """Query the simulation for the current state of our observables of interest.