Ensure that we use bytes literals for tid values.

Remove non-comment / docstring use of backticks.

repr() must return text, and we need bytes.

repr() must return text, and we need bytes.

       way that made other tests fail spuriously.

Fixed: An unneeded left-over setting in setup.py caused installation with
  pip to fail.

too fast.

too fast.

when running setup test.

Clean up dependency and setup test support.

(setup test fails because of circular imports)

we don't run tests for transaction here either.

Use a 'lazy string' class to compute the path to the persistent egg for
injection into the 'include_dirs' argument of the extensions.

This is a demo, which needs tweaking once 'persistent' is released to PyPI.