3.0.0-alpha9

Fix deprecation warnings with utf8_encode/decode
Merge pull request #16 from amulet1/improve_array_utils
feat: Add support for extra key in setElement() method
feat: Add support for extra key in getElement() method
fix: Reimplement setElement() * Make it non-recursive * Do not modify $keys * Do not return value
fix: Reimplement getElement() * Make it non-recursive * Drop $value parameter (setElement can be used instead) * Do not modify $array or $keys * Return null on error
feat: Add getFieldParts() to split field into path