Add a mean-centering vector normalizer
Freeze user vector for neighbor finding

The user to find neighbors for can be frozen, so that its norm is cached.
Add more logging on task completion
Use Maven plugin for external builds

This uses my new Maven plugin for out-of-tree builds, instead of
the in-POM scripts from grouplens-oss-parent.
Update 2.0.3 release notes [skip ci]
Generate list of public classes in each JAR (#392)
Create class directory to load class lists from JARs (#392)
Print help on missing property (#392)

If a missing property matches the name of a public class, print the classes the user may have wanted to import.
Fix bugs in error reporting

- Ant target list is strings
- Throw cause of Groovy exception, not exception
Refactor logging for color

- Move eval logging config to lenskit-package
- Add color support with JAnsi
Convert Maven logging config to XML
Add eval improvements to release notes. [skip ci]