switch to maven build

— created a pom.xml file using groovy-eclipse-compiler
  as documented here :
  → http://groovy.codehaus.org/Groovy-Eclipse+compiler+plugin+for+Maven
— moved files to get closer to standard project layout
  src/… → src/main/java/…
  src/test… → src/test/{java,resources}/test…
— replaced lib/… with maven dependencies
— removed build results and eclipse project files (updated .gitignore)
Attached sources and shaded uberjar as sources and all maven artifact classifiers
Merge pull request #1 from lea-raya/feature/mavenized

Feature/mavenized