Tycho should provide a WorkspaceReader

[laeubi]

Currently we inject maven dependencies into the maven model as "system-scoped" dependencies. System-Scope is deprecated and we only do it to prevent maven from trying to resolve those dependencies.

More maven-concentric would be, that we add the dependencies as "normal" dependencies and provide a WorkspaceReader that resolves these artifacts to the corresponding P2 data of the project.

Still there are some issues from the maven side before we really can do this see:

• MNG-7401 - Make MavenSession#getCurrentProject() using a thread local apache/maven#666
• https://issues.apache.org/jira/browse/MNG-7400

as currently there is no way to know what project actually requests the current dependency from the WorkspaceReader component and we would be required to register this as a core-extension using some nasty hacks to get our WorkspaceReader actually considered.

[laeubi]

Just a minor issue: https://issues.apache.org/jira/browse/MNG-7496