Merge SBML branch to unstable

[ugurdogrusoz]

Before Newt 4 can be tested and released the new SBML feature needs to be merged into the unstable branch as it was developed on this separate branch. But we need to do this for multiple repository as the SBML feature affected all these repos:

• sbgnviz.js
• chise.js
• newt.js
• our Cytoscape.js fork

So, merge the SBML branch in all of these repositories to the unstable branch of the same repo in your local and do the tests there. Once you feel comfortable, you may go ahead and push the changes to the unstable branches.

[ugurdogrusoz]

@NoorMuhammad1 If no reason to keep this open, please assign this back to me, and I'll close it.