[~BUGFIX] FLOW3 (Validation): The ValidatorResolver test case failed - but only if the Blog package was installed. This was due to some Blog model being used by a data provider which in reality should have been a sample, not existing class. Fixed that.
[~TASK] FLOW3 (Validation): The TextValidator was too restrictive because it did not allow line breaks and other common characters - now it does. However, it's not really secure yet. Relates to #3977
[+BUGFIX] Fluid (Core): Added some safe guard and aception to the Abstract Node which would exit with a fatal error in some cases.