Adrian-Devries

The following references are incorrect: `./trunk/README.md:10:* Silverlight, Windows Phone 7, and Windows Metro (WinRT) using [SilverlightGraphics.cs](https://github.com/praeclarum/CrossGraphics/ blob/master/SilverlightGraphics.cs)` `./trunk/samples/Clock/ClockSilverlight/ClockSilverlight.csproj:75: ` `./trunk/samples/Clock/ClockSilverlight/ClockSilverlight.csproj:76: SilverlightGraphics.cs` `./trunk/samples/Clock/ClockWP7/ClockWP7.csproj:64: ` `./trunk/samples/Clock/ClockWP7/ClockWP7.csproj:65: SilverlightGraphics.cs` `./trunk/samples/Clock/ClockWpf/ClockWpf.csproj:65: ` `./trunk/samples/Clock/ClockWpf/ClockWpf.csproj:66: SilverlightGraphics.cs`

Update plugins and dependencies, migrate to JUnit5 and fix issues

6

Some weeks ago the branch [release/1.5.x](https://github.com/itplr-kosit/validator/tree/release/1.5.x) has been added. This pull request includes the changes made there. In addition, it updates plugins and dependencies to the most recent versions, it...