Major Description
There needs to be an easier way to introduce new filters into the chain. I've been thinking that we can provide two "out-of-the-box" providers (e.g. pre-chain-filter and pre-dispatch-filter or initial-filter and final-filter, etc.). If enabled they would contribute a filter using one of the params as the class name. All other params would be used as filter init params. All current service contributors would need to be changed to always include these filters in the chain.
Design proposal:
https://cwiki.apache.org/confluence/display/KNOX/Simple+way+to+introduce+new+Provider+(KNOX-179)