Changes how filter_var is used on validate()
Changes how filter_var is used on validate()

Add: Boolean filters are now raising model errors on FALSE result. Those
errors will be added to the models error stack under the key of current
data.


Signed-off-by: Michael "Tekkla" Zorn <50f195679bf77bf0955b9c2832e55e1d0c47d29c@tekkla.de>
tekkla/TekFW,tekkla/TekFW