Use Java NIO library instead of native code to create and detect symbolic links and Windows junctions to improve compatibility and robustness.
(issue 36088, issue 39179)
Prevent concurrent installation of Maven on the same node to prevent problems.
(issue 34138)
Developer: Deprecate the ambiguous User#getUser(String) in favor of the User#getById() or the new User#getOrCreateByIdOrFullName() methods.
(issue 47718)
Developer: Implement default methods in TaskListener and BuildListener interfaces so they don't have to be implemented in subclasses.
(pull 3122)