LUCENE-3944: Make the 'generate-maven-artifacts' target use filtered POMs placed under lucene/build/poms/, rather than in each module's base directory. The 'clean' target now removes them.
SOLR-3200 and SOLR-3226: fixing SignatureUpdateProcessorFactory to include non-String values, and to deal with the 'all fields' case correctly (merge r1308604)