Initial helpful debug features for Build Tools

This doesn't add any error handling/useful output to each tool.  Instead this first PR simply adds a helpful 'help' mechanism if an incorrect command or no command is used. For example:

```
$ origami foo
foo not a command
Available commands:
install  -  Installs Origami and module dependencies
build    -  Builds the Origami module Optional: --watch
test     -  Runs the test suite Optional: --watch
demo     -  Builds the demonstrations Optional: --watch
verify   -  Verify the module's conformity to the specification Optional: --watch
```

This PR restructures the command definition, rather than using `if` statements akin to switch statements, it's now more declarative and should be clearer to update in the future.

This doesn't add much really but is at least a start on issue #3.