pom.xml: configure to using groovy eclipse compiler.

@see http://groovy.codehaus.org/Groovy-Eclipse+compiler+plugin+for+Maven
CatalogUtilsTest: partially ported to Spock+Groovy
removed TODO
ported more
migrate to gmaven-plugin

http://code.google.com/p/spock/wiki/HelloSpockPom
https://groups.google.com/forum/?fromgroups=#!topic/spockframework/u2xh6_EgUhY
https://github.com/spockframework/spock-example/blob/master/pom.xml
pom.xml: get rid of duplicates and old artifacts from groovy-eclipse-compiler
CatalogUtilsTest: removed (use Groovy version)
TODO: added
Updated Groovy
fix spelling
Ported rest of test cases
fixed rebase
move plugin version to property
deleted TODO