validation-xml

add sequence and attribute pick filtering

add of common rules fort primitive types

remove parenthesis

add of option handling

remove println

add example validation repos in readme

validation from non-leaf node to string is now invalid

clearer non-leaf error validation msg

improve test syntax

add nodeDoubleR

better test with seq

safer attribute filtering

refactoring of attributes for better correctness

remove old test comment

more robust pickInS

clearer nodeR

fix pickInS for empty collection