Add Menu Entry to toggle wave caching on/off

[MichaelHuth]

Add a togglable menu entry to globally disable wave caching when enabled.

This helps testing in development where otherwise one would need to clear the cache on every attempt.

[t-b]

I'm not a fan of having more menu entries. We could add a define like DEBUGGING_ENABLED though with functions to enable/disable it. Feel free to tackle this.

[t-b]

Let's add this define.