Removed external filtering feature, too dangerous

Reason: Systems were thrown into infinite loops if only single
improper command was executed by the filter (improper means that
command path was not in the exclusion list).

The decision was:
- remove external filtering
- implement internal filtering
- internal filtering must be configurable
Removed configure file, added autogen.sh to generate configure file on the fly, fixed documentation
Removed stale filtering contents (readme and header defines)