Switch from hibernate hbm2ddl update to flyway

It's actually safer to do this on our own, especially if we don't want to lose data.
Implement proper display of deployed and deployable versions
Make login bean request scoped
Switch to server action evaluation

Otherwise sometimes the links fail for no obvious reason
Skip projects without versions

If a project does not have a version yet it would add a null to the result list.
Improve detail page layout
Add default ordering where simple and appropriate
Instantiate DeploymentCalculator only once
Add simple overview of all deployable versions for all servers
Improve layout of the login page