* Add instructions for an internal proxy provider
* Improve example test config
* .. by moving CSAF_CONFIG out of the common fcgiwrap.conf,
so it can more easily be changed in a different context.
* Improve proxy-provider-for-aggregator.md
* Add section to aggregator documentation.
* Fix typos.
* Improve instructions.
* Fix one path
* Complre proxy-provider-for-aggregator.md
