Version 1.5.6

Add missing files from 1.5.5 merge

Review URL: https://codereview.chromium.org//371913004

git-svn-id: http://dart.googlecode.com/svn/branches/1.5@38031 260f80e4-7a28-3924-810f-c04153c831b5
diff --git a/tools/VERSION b/tools/VERSION
index ae98bff..7a8f7e4 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -26,6 +26,6 @@
 CHANNEL stable
 MAJOR 1
 MINOR 5
-PATCH 5
+PATCH 6
 PRERELEASE 0
 PRERELEASE_PATCH 0