Manual entry of missing license information

[javadude]

Some third-party libraries are missing license information in their POMs.

Add support for manual specification of known licenses for these libraries.

The license information usually comes from a LICENSE file in the library's repository (sometimes you need to contact the author to ask them to create one).

This plugin should report libraries that are missing license information in the POM and have not been manually specified. This should be a warning for a debug build, error for release build, if possible.

Ideally the plugin should include simple instructions on locating the LICENSE info (mainly check repository - if listed in POM, state which repo to check)