[x3d-public] X3D python effort, suggested upgrades to x3d.py

[John Carlson]

>> We already have XML and JSON parsing for Java.
>
> X3D JSON is a TODO item.
>
> * X3D Java Scene Access Interface Library (X3DJSAIL) Conversions
> https://www.web3d.org/specifications/java/X3DJSAIL.html#Conversions
>
Here's a path forward!

https://sourceforge.net/p/x3d/code/HEAD/tree/www.web3d.org/x3d/stylesheets/java/src/net/coderextreme/X3DJSONLD.java

Plus sample conversion (must run in correct folder, 
/c/x3d-code/www.web3d.org/x3d/stylesheets/java/src), inputs/outputs 
from/to ../examples:

https://sourceforge.net/p/x3d/code/HEAD/tree/www.web3d.org/x3d/stylesheets/java/src/net/coderextreme/JsonConversion.java

But yeah, if you want separate methods for each node/statement type, one 
will have to do some work!

Also, I believe I have not totally round-tripped the HelloWorld 
example.  I'll do some work on that now.

John