Merge pull request Codeception#2645 from Naktibalda/asserts-hhvm-warning

Added warning to docs that Asserts module does not work on HHVM

fixed PO generator tests

updated changelog

doctrine2 strict compat fixed

not fire before and after events for skipped tests. Introduce skip an…

…d incomplete annotations for Cest classes

updated changelog

updated stable branch

fixed robofile

RC release prepared

updated changelog