Add LICENCE and NOTICE files to the jar

This patch provides a simple mechanism for adding the license files until the more flexible approach described in MJAR-10 can be implemented.

• default values should be given with default-value instead of an initialising value (the basedir won't be correctly aligned otherwise)
• this technique won't work especially well with multiple modules projects
• I'm not sure we want the Apache-specific NOTICE file in here. Perhaps it should be a part of the license specification.

Isn't a better workaround just to use the <resources> mechanism for this?

The license and notice files in the root of a project isn't a Maven standard (is it?) and plus I don't think it's a great idea anyways as it becomes repetitive in systems with large numbers of modules, all under the same license.

I think a better idea is to add an element to the MANIFEST.MF with the value(s) of project.licenses.license:

License-1-Name: Apache License, 2.0
License-1-Url: http://apache.org/APL-2.0.txt
License-2-Name: GNU Lesser General Public License, 1.1
License-2-Url: http://gnu.org/LGPL-1.1.txt

This way all modules can inherit their licenses via parent and have the manifest populated automatically.

I'd like to recall that Maven is an Apache project. In other words, if there is something like "Apache-specific", then the "Maven standard" should at least make it possible to follow.

Additionally, I'd like to point out a problem with Bretts suggestion to use the <resource> mechanism: If I do specify a resource, which lives in the base directory, then I'll encounter problems while building a source jar: The maven-source-plugin will include my whole project into the jar file. (This may be a bug in the maven-source-plugin, I am unsure what to think of it.)

This is now dealt with by the remote resources plugin.