Debounce post settings events

This fixes #1582.

I wrapped the relevant event handlers in `_.debounce` with a buffer of 0.5 to prevent over-eager updates.

I also changed the `toggleStaticPage` function to use the actual checkbox property because otherwise after the function is run it would only inverse the current setting.  So clicking the checkbox 3 times (back to the initial state) would end up just toggling it to the opposite. 

Let me know what needs modifying, I didn't fully understand the issue but this is my first shot at fixing it.