[MDEP-488] Build-classpath for maven repository layout

**[Gaël Lalire](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=gaellalire)** opened **[MDEP-488](https://issues.apache.org/jira/browse/MDEP-488?redirect=false)** and commented

Build-classpath cannot create a classpath for a maven repository layout in multimodules projects.
Indeed project.artifacts returns artifacts whose file may be from the local repository or from your project target directories.
For last one the replace mechanism failed.
We could execute the build-classpath with invoker plugin as a workaround but it is not clean.

I propose to make it possible with following configuration

```
${project.build.directory}/unix-classpath.txt
:
/
repository
true
```

---

**Affects:** 2.10

**Attachments:**
- [classpathPatch.diff](https://issues.apache.org/jira/secure/attachment/12734878/classpathPatch.diff) (_17.50 kB_)

Start with the build-classpath goal and review the attached classpathPatch.diff, focusing on the proposed repository-layout configuration. Verify the behavior for multimodule projects where artifacts come from project target directories, and confirm that the configured classpath output is produced correctly.

Written by the indexing model from the issue text.