views fusion compatibility for table sorting

I recently fixed views_fusion to don't prefix the $field['fullname'], because views uses this name to get $field_info. This is working now, but generated another problem: "dynamic" sorting with tablesort_sql() broke, because the constructed header also uses $field['fullname'].

Attached is a small patch which changes the header to use $field['queryname'], which works with views_fusion too.

So I'll suggest to stay with the distinction:
$field['fullname'] - not alias-prefixed name of the field
$field['queryname'] - name of the field in the query, so it might be alias-prefixed

attached is the patch for 4.7.x