Derived Feature Handlers fail-silent when matcherfactory cannot be loaded

[ujhelyiz]

When a derived feature is used, but the corresponding pattern definition is not available (e.g. missing plug-in in host in my case), the derived feature handler swallows the issue and ignores the issue.

All subsequent queries of the feature return an empty match; no log message or exception is available anywhere. Please, address this issue, as it is quite hard to debug.

[abelhegedus]

The matcherfactory check is added now.