Autotest ONIE

This is beginning of the testing framework for ONIE.

At the moment, it provides just the groundwork:
* Parameter validation
* Dynamic module loading
* Dynamic test definitions
* Basic documentation
I might be missing something obvious, but I have a really _basic_ question:

* What is this script doing?

`configure_test()` is simply printing out the name of the test. Where is the test getting executed?