Shortened Hebrew months are not parsed

When the date uses the full month name (i.e. "June"):
```python
# works correctly
>>> parse('1 ביוני 2014')
datetime.datetime(2014, 6, 1, 0, 0)
```
But when using a shortened month name (i.e. "Aug."):
```python
>>> parse('31 באוג׳ 2014') is None
True
```