- renaming of instance variable specific primitiva for more constistency with ::xotcl::importvar: ::xotcl::exists -> ::xotcl::existsvar ::xotcl::setinstvar -> ::xotcl::setvar
- removed the following classes and methods ::xotcl::Attribute->check_single_value ::xotcl::Attribute->check_multiple_values ::xotcl::Attribute->mk_type_checker class ::xotcl::Attribute::Nocheck