Make train-test data available in execution info (#600)
Add instance qualifer `get` to LenskitRecommender (#596)
Implement rating writer interface & CSV writer
Use new rating writers in crossfold task
Use new rating writers in subsample task
Implement packed rating writer (#587)
Support packed output in crossfolder (#587)
Bump Java source version for annotation processor (#569)
Include custom JavaDoc taglets

This drops our dependency on gl-common, implementing the JavaDoc taglets directly in the LensKit source tree.
Split JavaDoc into separate build file
Add MathJax footer to JavaDoc build (#592)
Add saner SimilarityMatrixModel constructor (#523)
Fix build system license headers
Fix MathJax footer
fix license config on Java 6
Merge pull request #602 from elehack/feature/elehack-2.1-fixups

Various 2.1 fixups