* mark data read from DB (req. for string key where existing key value is not reliable indicator for DB data)
* detect distributors by part of model string
* use a simplified name (no spaces, no special characters) to find a match
* allow to obtain model strings (=keys) as set and list
The following issues were fixed
* Fixed wrong/missing namespaces
* Fixed obvious typos in documentation
* Documentation not in sync with source code
refs #544
* common base class for DB based classes
* common base class for DB based containers
* Livery, distributor value class
* adjusted value classes to livery
* utility functions for DB values (blackmisc free functions)
* register new objects with metadata system