Migration from Bootable JAR Maven plugin 2.0.0 to 3.0.0

[jfdenise]

Here is the list of changes that you could have to apply when migrating from 2.0.x to newer version.

• In 3.0.0.Final we have fixed the extraServerContent configuration element to be extraServerContentDirs. That was required to align its name with the extra-server-content-dirs alias. If you are already using extra-server-content-dirs (that is the advised way), then nothing change for you, if you are using extraServerContent, you will have to update your pom file.