Merge pull request #825 from phpmd/changlog-2.9.1

Add Changelog for 2.9.1

Merge pull request #795 from TJVB/changelog_2.9.0

Prepare a changelog for version 2.9.0

Merge pull request #733 from kylekatarnls/feature/732-serialize

Fix #732: Add __serialize and __unserialize to list of ignored methods for camelCase rule

Add 2.8.1 changelog

Require pdepend 2.6

Require pdepend 2.6

Merge pull request #696 from phated/master

Add "For Enterprise" page to PHPMD website

Merge pull request #642 from phpmd/release-2.7.0

Release 2.7.0

Update changes & changelog

Changes documented and new release prepared.