Called to process data that was returned from the server.
requestComplete(status, cmd, [callBack])

status | string, status of the request
cmd | string, name of the command
callBack | function, optional call back function

Returns undefined.

#### Description

This method is called when server request returns. First parameters is the status of the request. If status = 'error' it indicated that request came back with an error. This method will merge returned data to the grid. It uses internal variable w2gird.request_xhr.responseText as the text returned from the server.
This method emits onLoad event.