Parameter Dependencies

This code adds the ability to show and hide parameters depending relevance (determined by another parameter).

It adds two new keys to the getParameterDefinitions array: 'depends' and 'dependvalue'.  If the former is defined, the latter must also be.

I have one concern with this code but I don't know what to do about it.  The formatting of the parameter table doesn't seem to be as consistent as it was before I applied this patch and I'm concerned this is a regression.  However, my knowledge of html formatting is close to zero and I don't know what to do about this.