[PATCH] BasicPreferences Test Isolation

[taylor.smock]

This is a followup of comment:13:ticket:21064 (Don-vip):

Thanks! For this ticket I'll stick with the simple solution, even if not ideal. Isolating unit tests is a long-term task.

As in comment:12:ticket:21064, the two patches attached to this ticket do the following:

• attachment:21139.patch​​ iterates through all loaded classes (I make an assumption that we only have one classloader), and sets all AbstractProperty preferences fields to the new preferences. This uses reflection to fiddle with final fields, which has some pitfalls.
• attachment:21139.2.patch​​ is the same as attachment:21139.patch​​, except it additionally resets the preferences fields to null. This is better from a test isolation view, but I can almost guarantee that additional tests will fail.

[taylor.smock]

Reset all static AbstractProperty preferences fields to the new Config.

[taylor.smock]

Additionally reset static AbstractProperty preference fields to null after each test (this may cause other test failures)