Run property auto-generation scripts as part of a grunt target

[alice]

https://github.com/GoogleChrome/accessibility-developer-tools/blob/master/scripts/parse_aria_schemas.py and https://github.com/RickSBrown/accessibility-developer-tools/blob/master/scripts/aria_rdf_to_constants.xsl - anything else?

[ricksbrown]

This task should also include investigating the feasibility of, and implementing:

1. 'Dumbing down' the scripts to the point that we delete them and instead do '1 for 1' transformation from XML to JS/JSON (using something like http://www.bramstein.com/projects/xsltjson/).
2. Generating a separate closure "module" for each input file and then relying on closure compiler / grunt to include them in the final output script as part of the standard concatenation routine.