Made valgrind optional. Capture the target output.

Don't fail if valgrind (system version not the google3 one) is missing.
If the test fail, print the output of the test.
Added .pyc to the gitignore file.
diff --git a/testrunner/runtest.py b/testrunner/runtest.py
index a87f9b5..05d29ec 100755
--- a/testrunner/runtest.py
+++ b/testrunner/runtest.py
@@ -369,10 +369,13 @@
       if run_command.RunHostCommand(f) != 0:
         logger.Log("%s... failed" % f)
       else:
-        if run_command.RunHostCommand(f, valgrind=True) == 0:
-          logger.Log("%s... ok\t\t[valgrind: ok]" % f)
+        if run_command.HasValgrind():
+          if run_command.RunHostCommand(f, valgrind=True) == 0:
+            logger.Log("%s... ok\t\t[valgrind: ok]" % f)
+          else:
+            logger.Log("%s... ok\t\t[valgrind: failed]" % f)
         else:
-          logger.Log("%s... ok\t\t[valgrind: failed]" % f)
+          logger.Log("%s... ok\t\t[valgrind: missing]" % f)
 
     # Run on the device
     logger.Log("\nRunning on target")
@@ -380,9 +383,15 @@
       full_path = os.path.join(os.sep, "system", "bin", f)
 
       # Single quotes are needed to prevent the shell splitting it.
-      status = self._adb.SendShellCommand("'%s >/dev/null 2>&1;echo -n $?'" %
+      output = self._adb.SendShellCommand("'%s 2>&1;echo -n exit code:$?'" %
                                           full_path)
-      logger.Log("%s... %s" % (f, status == "0" and "ok" or "failed"))
+      success = output.endswith("exit code:0")
+      logger.Log("%s... %s" % (f, success and "ok" or "failed"))
+      # Print the captured output when the test failed.
+      if not success or self._options.verbose:
+        pos = output.rfind("exit code")
+        output = output[0:pos]
+        logger.Log(output)
 
       # Cleanup
       self._adb.SendShellCommand("rm %s" % full_path)