added inline helper functions for better portability, might be useful
Fixed iniparser use and added some checks

- iniparser value usage fixed
- added some checks on several things:
    - is the configuration member available?
    - is the configuration required, what if yes but it is not available?

Latter two things are not implemented yet, as I'm not sure how to handle such
errors. Maybe it would be best to fail the whole software if the configuration
is not available but required.
Merge branch 'module_helper_functions' into core