Add "settings" and "toggle autoplay" features

[rhine3]

There are currently buttons for these two features. However, they aren't implemented yet, so the buttons should be removed until further notice.

• Settings: Enable user to change spectrogram generation settings and any other relevant settings, including toggling whether sounds automatically play when opened.
• Toggle zoom: Allow user to zoom into or out of spectrogram. This was implemented at one point but since broke.