JUnitFormatter: use ascending numbering of outline scenarios

Currently the JUnitFormatter use descending numbering in the names of the instantiated scenarios from scenario outlines, which seems a little unnatural. That is (the name attribute of the testcase xml element):
```
name="outline name_2"
name="outline name_1"
```
Because the JUnitFormatter relies on calls to the examples method to determine the number of instantiated scenarios, the numbering is not applied at all when using the JUnit runner, then all testcase element instantiated from the scenario outline will have the value in the name attribute. 

Change theJUnitFormatter to use ascending numbering, and make it work also with the JUnit runner. Basically:
```
name="outline name"
name="outline name 2\"
```
Also take into account that the scenario name may contain outline argument which are replaced with values from the examples tables. That means only apply numbering of the consecutive instantiated scenario names are the same.