already partly implemented / #1862

Hi madlyr. I already implemented some parts of this feature (the complicated parts).

As you can see in at this installation, there already is a project option called "Versions". Versions are actually closed Milestones. What's missing right now is...

• A clever way of closing tasks in the quick edit function (ask for resolve reason, version and comment")
• Moving all tasks "resolved in next released version" to this newly released version.
• Design and adjust the layout of project Versions