Implement the embedded jmol viewer

[stakemori]

See #28.

[EmmanuelCharpentier]

It could be interesting to implement intine threejs, which is a standard package starting with 7.5.beta3, IIRC. This gives HTML+javascript, which might be better supported than the Java spit out by jmol...

[stakemori]

@EmmanuelCharpentier, thank you for letting me know. I will consider it when I try to implement this.