- Actually check the contents of the file created by bdist_dumb.
- Don’t use “RECORD” as filename for non-PEP 376 record file
- Don’t start method name with “_test”, it smells like a disabled test
  method instead of an helper method
- Fix some idioms (assertIn, addCleanup)

Patch by Justin Love.

Patch by Jeff Ramnani.  Tested with -B, -O and -OO.

Patch by Hallvard B Furuseth.

I have tests to add in this file and it’s always nice to start from a
clean base.

instead of the locale encoding.

instead of the locale encoding.

sdist used to crash with a full traceback dump instead of printing a
nice warning with the faulty line number.