[MNG-5659] Project level settings.xml

[nielsbasjes]

JIRA issue: https://issues.apache.org/jira/browse/MNG-5659

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I'm one of the committers for Apache Avro and Apache Flink.

---

This is a first attempt to make it possible to automatically read a settings file which is part of a project. The situation where this is useful to me is in multi module projects within a company where a mandatory mirror must be used.

The initial version of this pull request is incomplete as it is only the code to make it work, no tests and no documentation at this point.
I will write all of those once you have approved the basic implementation direction and the core choices I have made so far.

Right now:

• The default assumed location is ${project.basedir}/.mvn/settings.xml
• If this file is present it is read with
  • a prio higher than the global settings
  • a lower prio than the user settings; I'm unsure if this is correct.
• It is the same file spec as the normal settings.xml, yet in the project level context some of those settings may not make any sense.

Looking forward to your feedback.

[oymy]

expecting this feature

[gnodet]

Superseded by #1059