Using more than one instance of `WP_UnitTest_Factory` causes all kinds of craziness, due to out-of-sync internal generator sequences. Since we want to use `setUpBeforeClass`, we were creating ad hoc instances. To avoid that, we were injecting one `static` instance via Dependency Injection in `wpSetUpBeforeClass`. All tests should really use the `static` instance, so we will remove the instance prop `$factory`.
Replace `$this->factory` with `self::$factory` over 2000 times.
Rewrite all of the tests that were hard-coding dynamic values.
#YOLOFriday
git-svn-id: https://develop.svn.wordpress.org/trunk@35225 602fd350-edb4-49c9-b593-d223f7449a82
