* documentation and script updates trying to fix#1647
* preparations for refactoring target/bin/
* complete refactor for target/bin/
* changing script output slightly
* outsourcing functions in `bin-helper.sh`
* re-wrote linting to allow for proper shellcheck -x execution
* show explanation for shellcheck ignore
* adding some more information
* new setup.sh function, new tests, new script and some minor updates to main.cf
* fix for missing files
* removed obsolete test-files
* restart postfix if neccessary.
* see pr #845
* fixed typo
* fixed branchmixup
* changed postfix reload command & changed to operate on container instead of image
* reload postfix only on adding new restriction
* main.cf is only changed when user is added.
- Postfix reload changed
- working on container instead of image now in setup.sh
- added cleanup after tests
* moved cleanup to makefile