php 5.6 is not yet released, so use 5.6.0-dev here
fix unzerialize regression in most of the case
Merge pull request #176 from remicollet/issue-phpreg

Version 2.0.9/2.1.4 breaks some test suites
Merge branch '2.0' into 2.1
Merge branch '2.1' into 2.2
Merge branch '2.2'