Provide sensible defaults for launch script properties when building with Gradle

[oneiros-de]

The gradle plugin sets the values of initInfoProvides, initInfoShortDescription and initInfoDescription to default values that are not taken from the project (e.g. "spring-boot-application"), while the maven plugin uses values from the project (e.g. ${project.artifactId}).

The gradle plugin should also use values from the project.

[philwebb]

Are there any common properties that we can use for Gradle builds? I think the main reason we left it out was there wasn't an obvious candidate.

Perhaps we can use jar.baseName?

[snicoll]

@wilkinsona wondering if this one is still applicable with the rewrite of the plugin in 2.0

[wilkinsona]

Yes, it's still applicable. Let's look at in 2.1 and either implement something or close it.