Can't load same demo after loading from database

[kdahlquist]

Do the following actions on beta:

• load Demo #2 from side panel
• load a grn from the database
• try loading Demo #2 again from the side panel--it doesn't load

I think this is because Demo #2 is still showing up in the side panel and clicking on it again doesn't do anything. I can load it from the Network menu OK.

[dondi]

This appears to break down into two distinct buggy behaviors:

• It should be possible to re-load the same demo; this resets the demo network to the original force-graph setup. The Network menu and Demo menu versions of this dropdown behave in this manner; we should find a way to make the sidebar version do the same
• If a demo is selected but the user then opens something different (e.g., a file or a database network), then the sidebar select element should reflect this by reverting to “Select a demo”

If it becomes necessary to separate these into their own issues, we can do so