New rule for easy temp dir creation in target folder

This makes it easy for testing something with the overview plugin so you can inspect the crawl result after the crawl. The rule might be re-used in other plugins as well, so I've put it here.
Fixed the pom to contain JUnit
Merge branch 'master' of github.com:crawljax/crawljax into new-test-util-rule
Removed system.out statement
Add a toString for the ProxyConfiguration
Better toString for some objects. Reduced mutability
Merge branch 'master' of github.com:crawljax/crawljax into new-test-util-rule
Merge pull request #106 from crawljax/new-test-util-rule

New test util rule