Add new module to aggregator POM releases all modules in the project

[manoswerts]

When adding a new module to the project, the aggregator changes. This causes all the modules to be released in the project even though they have not changed.

We should:

1. Have more intelligent detection that can determine whether a change in the parent / aggregator POM has any impact on the release artifact. This option will probably be limited to modules only as it is quite difficult to know for sure whether there is an impact on referenced modules.
2. Have the option to set a flag to prevent releasing modules on parent / aggregator change.

[douglassparker]

A more fundamental issue is that ANY change a parent pom causues every module to be released. Ideally, only changes that affect the executable code should trigger a release. Changes that affect the build process only (e.g. adding or changing a unit test) or changes that only change the documentation (e.g. Javadoc) should not trigger a release. But it is probably unrealistic to expect that kind of sophistication from the plugin.

[kobynet]

The plugin maps between folders and modules, if folders, that map to a module, changes, all dependent modules are released.