[x3d-public] renewed development of X3D JSON support

[John Carlson]

I've split out JSON parsing from validation. Here are the important file 
that don't parse:

$ bash validate.sh 2>&1|grep Failed" "JSON" "parse
Failed JSON parse 
/c/x3d-code/www.web3d.org/x3d/content/examples/X3dForWebAuthors/Chapter15Metadata/XmpMetadataEmbedded.json 
SyntaxError: Unexpected token { in JSON at position 7402
Failed JSON parse 
/c/x3d-code/www.web3d.org/x3d/content/examples/X3dForAdvancedModeling/AudioSpatialSound/SplitChannels.json 
SyntaxError: Unexpected token { in JSON at position 6795

Looking really good!

John