- added parameter "incremental" to ::xotcl::Attribute: when set, one can use "object paramname add|delete $value" etc. - use setters with parameter constraints in slot optimizer - as a consequence, setting attributes via slot names is about twice as fast as before, when parameter constraints are used. - extended regression test
- added a "-nocomplain" option to ::xotcl::valuecheck - changed semantic of ::xotcl::valuecheck: per default, valuecheck raises an error or returns true. If "-nocomplain" is used, valuecheck returns 0 or 1 like implemented befor this change - extended regression test