Added Apache commons-lang3 to dependencies.

- I have no idea where the old commons-lang dependency is coming from (if anywhere), so I thought it might be a good idea to update this.
Ported a few methods.
Updated .gitignore to ignore Gradle cache.
Merge branch 'refactoring' into feature/gradle

- Also did a basic conversion of TestUtils to Groovy.

Conflicts:
	.gitignore
	src/main/groovy/org/dynunit/nucleus/TestUtils.groovy