Backfill aui 5.6.x (request)

Sources: https://bitbucket.org/atlassian/aui-dist/get/5.6.4.zip
https://bitbucket.org/atlassian/aui-dist/get/5.6.5.zip
https://bitbucket.org/atlassian/aui-dist/get/5.6.7.zip
https://bitbucket.org/atlassian/aui-dist/get/5.6.8.zip