Hierarchical POM Configuration DSL Implementation

[YongGoose]

Implement hierarchical POM configuration system through Settings plugin and project-level plugin.

[oleg-nenashev]

As discussed on Slack, reopening:

• The feature is not documented (README with a summary and an example would be enough)
• To be Decided by @YongGoose - currently, the code just supports four basic fields for override. While it works, it is not enough added value for a common user to justify adding a new plugin. We would need more fields (Support organization defaults for more fields #17 ) or DSL features - it can be done in a separate issue

[YongGoose]

I think this task is done.
What do you think? @oleg-nenashev