- Move helper methods for setting BukkitService mock behavior into their own class
- Change methods to use Mockito's answer instead of verification + argument capture -> calling the methods now belongs to the test setup (given clause) and allows the behavior to take effect more than once
- Create BukkitService#runTaskOptionallyAsync and BukkitService#scheduleSyncTaskFromOptionallyAsyncTask whose behavior depends on a new setting
- Use the new methods where applicable
- Declare events async or sync depending on the new setting
- Extract logic for walking through a directory and loading its classes into a separate class
- Replace all implementations with the new ClassCollector
- Move console initialization for tests into TestHelper
- Remove unused properties in legacy Settings
- Add issue number to TODO comments where applicable
