The 1.5.4 release is now out. However, some small stuff didn't make it and I'm considering a 1.5.5 release {1} before cutting master over to 1.6.x. I'm still on the fence, so I'll let you know when I decide. What I'm sure about is that there will be no 1.5.6 release out of master. If that were to happen, it would come from the 1.5.x branch.