[xmlunit/xmlunit] d6b8a9: fix some javadoc warnings

[GitHub <no...@gi...>]

  Branch: refs/heads/master
  Home:   https://github.com/xmlunit/xmlunit
  Commit: d6b8a9980f1dcd15b040a47952d00f63eab45cc7
      https://github.com/xmlunit/xmlunit/commit/d6b8a9980f1dcd15b040a47952d00f63eab45cc7
  Author: Stefan Bodewig <ste...@fr...>
  Date:   2017-08-26 (Sat, 26 Aug 2017)

  Changed paths:
    M xmlunit-core/src/main/java/org/xmlunit/builder/DiffBuilder.java
    M xmlunit-core/src/main/java/org/xmlunit/diff/DefaultComparisonFormatter.java
    M xmlunit-core/src/main/java/org/xmlunit/diff/DifferenceEngine.java
    M xmlunit-matchers/src/main/java/org/xmlunit/matchers/CompareMatcher.java

  Log Message:
  -----------
  fix some javadoc warnings