XMLUnit for Java 2.6.1 Released

This release adds a new module with AssertJ support thanks to the lates XMLUnit project member Krystian Kałużny.

The full list of changes is:

• add a new module with AssertJ support. This module requires Java7 at runtime.
  Issue #117 via PRs #120, #126, #128, and #129 by @krystiankaluzny.

• The XPathFactory used by the XPath related Hamcrest matchers is now configurable.
  Issue #131 via PRs #132