[FEATURE] Extension configuration toggle for all error handling

Can be used to switch on and off the Exception handling logic in all Flux controllers, rethrowing Exceptions without further processing if the feature is disabled.

Note: before this change the default behaviour was to always handle errors unless `plugin.tx_SCOPENAME.settings.displayErrors = 1`.
[DOC] Add missing doc comment annotation for thrown Exception
Merge pull request #214 from NamelessCoder/errorhandling

[FEATURE] Extension configuration toggle for all error handling