Improve ViewHelper exception handling
Currently, if a ViewHelper throws an exception, we catch that in the corresponding ViewHelperNode and simply output the exception message.
Instead, we should handle the exception depending on the current "context".
E.g. if in production mode, the exception should be silently ignored (and maybe logged instead). In development context, the message should be outputtet but probably with some more informations about the current template etc.
Question: in FLOW3/TYPO3 v5 we already have the notion of contexts. In v4 we don't have that yet AFAIK. Instead we could use the "devIPmask" setting to switch to development context.. Any ideas?