Xamarin parsing decimal units is locale dependent

Hi,
by creating a rule with decimal value, for example

```
.somerule {
    BorderWidth: 1.3;
}
```
the resulting value is dependent on system locale, i.e. for an English device, you will have 1.3, on an Italian device, you will get 13.
I suspect that the value is parsed according system locale, but it should be cultureinvariant.

Thanks
