[bugfix] [shared/oval, RHEL/6, RHEL/7, Fedora] Fix issue raised by pull request #52 - get rid of multiple not-synced copies of idtranslate.py & testcheck.py scripts

* Get rid of multiple not-synced copies of idtranslate.py script,
* Instead of using multiple copies of testcheck.py script make a testcheck_module.py Python module & make all the particular testcheck.py scripts to call this unified version,
* Add .gitignore file (to ignore *.pyc & *.ini files) for Fedora/input/checks & shared/ directories

This is a blocker / prerequisite for the pull-request https://github.com/OpenSCAP/scap-security-guide/pull/52