Numbers starting with dot should be accepted

[efreibe]

Hello, I think that numbers with format like .123 should be accepted as a valid number.
A lot of users are accustomed to write like that in input boxes.

See this example I took from chrome:

Even empty string is returning an exception but this is a valid number zero.

[a14n]

Thanks for the report. I agree as it's accepted by double.parse.

Fix available in 0.3.4