[Thumbnail Handlers] Support thumbnail handlers

[dantman]

We have configuration for various servers, however we do not have thumbnail handlers for all of them.

In order to implement thumbnail handlers in other server types we need people using those servers willing to experiment with configuring a thumbnail handler.

This issue is an epic, separate issues for server types without thumbnail handlers should be made as we add support for different server types.

• [x] Apache
• [x] LightSpeed
• [x] Nginx
• [x] Lighttpd
• [ ] #3