Does not support decimals without leading digits

```
For the decimal ".23" is not recognised by Parse.Decimal.

Fix: 
http://code.google.com/r/robert-sprache/source/detail?r=bc37605aba52ba0ced6d9268
8b2b1a9b18f60705

Most likely a more succinct way to do it though
```

Original issue reported on code.google.com by `rob...@wagner.id.au` on 21 May 2012 at 1:49
