Props converter update

Contains enhancements from @jrao and me

Note, because of the bad commit (https://github.com/jhinkey/liferay-docs/commit/fe40ec6c17f0b10023cc1878947c7cae615b6203) I had lying around my old origin/master, I had to re-do my branch and cherry-pick in Jesse's changes, as noted in parens in the commit comments. Sorry about that.

Rich, after you've handled all of my pulls, please let me know, so I can delete my origin, and re-fork to get rid of that bad commit. Thanks.