Deprecate xmlmap format, prepare a revised xmlmap2 format

```
Issue 127 shows a bug in xmlmap format. This bug can lead to backward 
compatibility issues which would not come up when using the json format. It 
would be better if xmlmap returned <number> elements consistent with JSON 
specification (instead of separate <int> and <float> types).
```

Original issue reported on code.google.com by `rygielski` on 17 Jul 2012 at 10:17
