Add 2.4.2 release notes
Merge pull request #578 from beav/242-relnote

Add 2.4.2 release notes
Merge remote-tracking branch 'origin/2.4-dev' into 2.5-testing
Merge remote-tracking branch 'origin/2.5-testing' into 2.5-dev
Merge remote-tracking branch 'origin/2.5-dev'