Better handling for engine's pre-getParser()

[revin]

Marky's getParser() method only became available in 10.x officially (which as of this writing isn't released yet), so for making the Debug tab work, we either need to just decide that it won't work for those old versions, or backpart the getParser change to any old versions of marky we want to use, and then bundle those for inclusion in our /js directory (this is how I created the 9.x ones currently contained in this repo).