Minor update

[FilomenoSanchez]

This update includes

• Closes Use AMISE bandwidth estimator  #133
• Calculate RMSD if distances are available when user creates a contact diff track
• Smooth values in diff track
• Update track selector layout to make it more clear when multiple tracks are available

[FilomenoSanchez]

Still a few things missing before we can merge this:

• RMSD colour scale should range 0-5Å
• When looking for diff info between distance predictions, cache lookup should not care about L factor
• Possibly should add information in the help page about the new contact density and contact diff tracks