There is way to cleanly evict all elements

[esp32wrangler]

I would like to cleanly drop the complete cache and call the evict callback on all elements. This is not currently possible, because:

• the Purge function doesn't call the evict callback
• Iterating over the Keys doesn't work, because there is no way to Get or Peek expired elements

Please add an option to Purge to call the eviction callback, or add a new function such as EvictAll

[rockdaboot]

Thanks for the request, sounds reasonable. I'll have a closer look at it soon.

[rockdaboot]

@esp32wrangler Please let me know if #49 satisfies your needs

[esp32wrangler]

@esp32wrangler Please let me know if #49 satisfies your needs

Thanks for the quick fix! It looks good, please merge and tag it so I can properly test it in my app.