site.sh-configurable KVM rollbacks

@@ -5,5 +5,10 @@
 # Uncommenting this line will create a on-disk repo in
 # the top level of your checkout and publish there instead
 # of the URI specified above.
 #
 #PKGSRVR=file:///$MYDIR/../tmp.repo/
+
+# These two should be uncommented and set to specific git changeset IDs
+# if illumos-kvm and illumos-kvm-cmd get too far ahead of illumos-{gate,omnios}.
+#KVM_ROLLBACK=a8ea37e8deb99265682c66c23f787f704e77fb91
+#KVM_CMD_ROLLBACK=1c6181be55d1cadc4426069960688307a6083131