p2publish: Deployment of dependencies

[michael-barth-elco]

p2publish can be extended processing the last prerequisite step 'Providing 3rd party dependencies'. This are dependencies taken from Maven repositories (instead of P2 repositories how it mirrorP2repository does). They will be provided as Maven repository (for gradle) and P2 repository (for Eclipse). The artefacts must be renamed be adding a prefix avoiding resolution against mcentral or jcenter. The dependencies in the manifests must contain this prefix too.

[michael-barth-elco]

There is a new plugin MavenArtefactsPlugin, which implements this requirements. Its better to split it into two plugins, because the configurations are quite different.