CPTreeNode: same-parent child moves no longer misplace the moved node — this corrects a defect in the class itself, properly exposed by the test.
Separately, the unit test's expectation for a root node's index path was itself wrong.
Corrected to match the class's existing, contract-correct behavior.
Test unit now runs cleanly.
Previously, every AppKit tests used the same sharedApplication. Due to this implementation, a could not pass because a previous test made failed the current test. For instance, a test could fail because the window of the previous test resigned (just imagine a new window is the key window in the current test), and this resign could raise an error. The error was displayed for the current test thought this test was perfect !
We now instead of using sharedApplication create a new CPApplication per unit-test file in the class method setUp.