Doing it the easy way with FilterFactory

A plan for the future is to create a FilterFactory, to make the process of making a new filter a simple process of specifying a few details, and writing a small amount of code to perform the actual data processing.

Unfortunately, this hasn't yet been implemented. It is also likely that when it is, it will not be possible to cover all the possibilities available by writing the boilerplate yourself, so some plugins will always need to be manually registered.