Pattern validation fails when the message is an empty string

When specifying the pattern binding, and the message is empty:

    this.value.extend({
        pattern: { params: Constants.NAME_REGEX, message: "" }
    });

Then in addExtenders call the wrong addRule method will be invoked, and upon processing of the pattern validation, it will not use the regular expression, but the actual params object, which will not work so well.

            if (params && (params.message || params.onlyIf)) { //if it has a message or condition object, then its an object literal to use
                return kv.addRule(observable, {
                    rule: ruleName,
                    message: params.message,
                    params: utils.isEmptyVal(params.params) ? true : params.params,
                    condition: params.onlyIf
                });
            } else {

Suggested fix:

            if (params && (params.message !== undefined || params.onlyIf !== undefined)) { //if it has a message or condition object, then its an object literal to use
                return kv.addRule(observable, {
                    rule: ruleName,
                    message: params.message,
                    params: utils.isEmptyVal(params.params) ? true : params.params,
                    condition: params.onlyIf
                });
            } else {

Start at addExtenders and inspect the branch that handles pattern parameters with an empty message. Verify the empty message is treated as a defined option while the regular expression remains the rule parameters, then confirm pattern validation works with message: "".