[MARCHETYPES-87] Warning on simple project creation

**[Elliotte Rusty Harold](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=elharo)** opened **[MARCHETYPES-87](https://issues.apache.org/jira/browse/MARCHETYPES-87?redirect=false)** and commented

Creating a basic project from the archetype has warnings:

[WARNING] Don't override file /Users/elharo/tmp/myartifact/src/main/java/com/elharo/sample
[WARNING] Don't override file /Users/elharo/tmp/myartifact/src/test/java/com/elharo/sample
[WARNING] Don't override file /Users/elharo/tmp/myartifact/src/site
[WARNING] CP Don't override file /Users/elharo/tmp/myartifact/.mvn

Regular usage should run without warnings.

---
No further details from [MARCHETYPES-87](https://issues.apache.org/jira/browse/MARCHETYPES-87?redirect=false)

Reproduce creation of a basic project from the Maven archetype and capture the warning output for the listed paths: src/main/java/com/elharo/sample, src/test/java/com/elharo/sample, src/site, and .mvn. Trace where those warnings are emitted, then verify that regular project creation completes without them.

Written by the indexing model from the issue text.