added to Model:
- method field() which can take a pointer to a member which returns bool:
void field(const wchar_t * field_name, bool (ClassName::*method)(), const morm::FT & field_type = morm::FT::default_type)
- method field() which can take a pointer to a member which can set morm::ModelWrapper object
void field(const wchar_t * field_name, void (ClassName::*method)(morm::ModelWrapper **), const morm::FT & field_type = morm::FT::default_type)
- methods: bool Model::convert_to_bool(...) - they are used for creating a result for ezc from local fields
methods before_field_value_string() and after_field_value_string() moved
from DbExpression and JsonExpression to BaseExpression and made virtual
and now methods before_field_value(const std::wstring &) and after_field_value(const std::wstring &)
(and the rest of them with string arguments) can be removed from DbExpression, PostgreSqlExpression and JsonExpression