Updated Shell__Command to latest upstream

Geoffrey Broadwell · Geoffrey Broadwell · commit d6349012226d · 2013-10-16T08:43:45.000-07:00
diff --git a/ext/Shell__Command b/ext/Shell__Command
@@ -1 +1 @@
-Subproject commit 2bff90ec2b12560d1072cfca3a1657dab0a0088c
+Subproject commit 1b89c9e18682897eb120b15885dbb3a502ecded0
