add "Export Data" option to file menu

[phtj]

We need to be able to save just the GI Data for a model

File menu > Export Data This will save a mobius file that only contains the data.

This will

• take the data in the end node and stringify it
• create a new mobius file with just two nodes and add util.ImportData function to the end node
  • set the data for the function to the data string
• take the name and description from the old mob file and copy to the new mob file
• add the parameter settings to the description as follows
  • for each parameter, copy over the description, name and current value
  • insert a <hr> between each parameter