2014-01-22: merge stable into default

merge stable into default

diff --git a/.hgtags b/.hgtags
--- a/.hgtags
+++ b/.hgtags
@@ -8,3 +8,4 @@ ce8ccd40ef936710e76200d2ee138535e4ab0fb4
 00de78a95055f846906d57b1a094a1c3e6bb2dbd v0.5.2
 df64e82e0920bdd079d77cd4829bac9d30461a25 v0.5.3
 f9c6e637d91d107bbf2ad807f30dc04150ddb251 v0.5.4
+3f72f85e4cddf57e5e6c84c735f554f330d3b88b v0.5.5