rawtext_search: Adds configurability of search delimiters

* Adds search delimiters to NonComplianceCheck and rawtext_search to
  remove a flaw, which would not allow to search for specific characters.

* Changes the configuration files to use // as regex delimiter.

* Some PEP8 and general code adjustments.

Signed-off-by: Martin Vesper <martin.vesper@cern.ch>