tddreloader

Adds a reloader (originally based on Mochiweb's reloader) and simple (maybe naive) eunit TDD test runner plugin. 
Look at what's been done for common_test for example:

```
You can add extra `ct_run` options by defining the  CT_OPTS  variable. For more information please see `erl -man ct_run`.
```

You can pretty much paraphrase that and replace ct_run with erl and CT_OPTS with SHELL_OPTS and people will know exactly what we are talking about.

Once that is done please squash all commits into one, push -f and that should be good.