GROOVY-7175: Add List.withIndex()
GROOVY-7175: add DGM withIndex methods
GROOVY-7175: add DGM indexed methods (has index, value ordering)
Merge pull request #559 from paulk-asert/groovy7175

Groovy7175
GROOVY-7171: Add List.getIndices()
GROOVY-7171: DGM getIndices methods (changed List to Collection and also added object array for completeness)
GROOVY-6952: Add List.removeAt(int) and Collection.removeElement(Object), because for List<Integer>, List.remove(int) and Collection.remove(Object) are troublemakers.
GROOVY-6952: Add List.removeAt(int) and Collection.removeElement(Object)
GROOVY-7212: Upgrade JUnit to 4.12
GROOVY-7175: add DGM indexed methods (javadoc typo)
Fix possible test failure depending on the order of execution of test methods