setting array values via special indexers do not refresh the view

```python
# .i .points .ipoints .iflat all "fail" to refresh the view
arr = ndtest((2, 3))
arr.i[0, 0] = 10
arr.points['a0', 'b1'] = 11
arr.iflat[3] = 12
arr.ipoints[1, 2] = 13

# works
arr['a0', 'b1'] = 42
```
the regex is most likely too strict