Eliminate dead home-made assertion-at-dev-time-only code.

The assertion code hidden in here, designed to allow development time
assertions than vanish at runtime - in the classic "better to keep working on
corrupt data and failed assumptions than fail in front of the user" mode - was
not actually used anywhere in the product.

We may as well not carry this little legacy around any further than it current
has been, then.

Signed-off-by: Daniel Pittman <daniel@puppetlabs.com>