Sets the source data object containing the property data.  The data object can contain one or more name/value
pairs representing all of the properties of an object to display in the grid, and this data will automatically
be loaded into the grid's {@link #store}.  The values should be supplied in the proper data type if needed,
otherwise string type will be assumed.  If the grid already contains data, this method will replace any
existing data.  See also the {@link #source} config value.  Example usage:

grid.setSource({
"(name)": "My Object",
"Created": Ext.Date.parse('10/15/2006', 'm/d/Y'),  // date type
"Available": false,  // boolean type
"Version": .01,      // decimal type
"Description": "A test object"
});

@param {Object} source The data object.
@param {Object} [sourceConfig] A new {@link #sourceConfig object}. If this argument is not passed
the current configuration will be re-used. To reset the config, pass `null` or an empty object literal.
function(source, sourceConfig) {
        var me = this;
        
        me.source = source;
        if (sourceConfig !== undefined) {
            me.sourceConfig = Ext.apply({}, sourceConfig);  
            me.configure(me.sourceConfig);
        }
        me.propStore.setSource(source);
    }