[MERGE] Convert tests.blackbox.test_d* to use internals where appropriate

[Aaron Bentley]

Aaron Bentley has voted tweak.
Status is now: Semi-approved
Comment:
More whitespace issues.  Otherwise good.

For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3C1187709078.6453.18.camel%40lapbert%3E