1150297 - Replace 2.4.x versions with 2.5.0.

https://bugzilla.redhat.com/show_bug.cgi?id=1150297
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'
Merge branch '1150297' into 2.5-testing
Merge branch '2.5-testing' into 2.5-dev
Merge branch '2.5-dev'