switched sonatype-repo to https to prevent redirects and switched to maven compiler plugin 3.1, to work with configured groovy eclipse compiler 2.8.0-01, as suggested on http://groovy.codehaus.org/Groovy-Eclipse+compiler+plugin+for+Maven
added support for a timestamp field, being dynamically filled upon indexing with a timestamp of the import.
The name of the field can be configured.