Issue submitted by Eugene Schava with patch:

I try to use int validator in javascript. I have found a bug: if i use only
only parameter (min or max) - freemarker throws an exception because another
parameter value is null... My offer:

            <#elseif validator.validatorType = "int">
            if (field.value != null) {
                if (<#if validator.min?exists>parseInt(field.value) <
${validator.min}<#else>false</#if> ||
                        <#if validator.max?exists>parseInt(field.value) >
${validator.max}<#else>false</#if>) {
                    addError(field, error);
                    errors = true;
                }
            }
            </#if>