* Adjusted validation
* Use default airline object when a color livery is created (refs #774 also)
* Added/improved completer strings (e.g. getVDesignatorDbKey())
* utility functions in lists
* 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
