Some util methods for adding options to tools.

* Simple helper methods which reduce the number of boilerplate lines when adding options to tools.
* If used generally, would standardise tool formatting for tool options. (e.g. defaults handling)
Yeah, that's it really. I included this method since it standardises the formatting of the help message. Unfortunately the apache cli lib doesn't have handling for default values so the user still needs to handle this themselves. I'll add a comment in the javadoc for this.