Publish the docs for Bamboo 4.2

Archive the existing docs to a BAMBOO041 space; delete 4.2 specific pages
Set up redirect for Bamboo 4.2 links to the BAMBOO space - create ADM pull request for puppetmaster repo ADM-26304
Rebrand the BAMBOO space to 4.2
Update the ALLDOC pages
Update the page footer
Publish the draft pages
Unhide the Release Notes and UpGrade Guide
Do the BAMBOOKB announcement
Do the 4.2 doc exports and update the ALLDOC list
update the EOL dates matrix in https://confluence.atlassian.com/display/Support/Atlassian+Support+Offerings