dataTable ajax

# Ajax request calls encode() methods of <rich:dataTable> even if it is not necessary

## Description

Any Ajax request reloads the list that is related to the <rich:dataTable> component even if the Ajax request is related to another bean. It happens because the Ajax request checks whether the <rich:dataTable> has nested <rich:outputPanel> or <rich:messages> components that should be updated. If there are no <rich:outputPanel>, <rich:messages> components inside the <rich:dataTable> will not be updated, but anyway the `encode()` methods is called by the Ajax request.

## Links

- Jira

- RichFaces Forum

## How to reproduce

Place the following code on a page and click the button. The list in `myBean1.myList` will be reloaded.

    ...
    <h:form  id="form1">
        <rich:dataTable id="myTable" value="#{myBean1.myList}" var="comp">
            ...
        </rich:dataTable>
    </h:form>
    <h:form id="form2">
        <h:outputText value="#{myBean2.test}"/>
        <a4j:commandButton event="onclick" reRender="form2" />
    </h:form>
    ...

## Causes

Bug is caused by <rich:dataTable> implementation peculiarity.

## Workarounds

Wrap the zone of a page that should be processed and updated in the <a4j:region> component with `renderRegionOnly="true"`. The <rich:dataTable> should be outside of the <a4j:region>.