CreateUri formats the query parameters with ";" instead of "&"

Hi,

When using the CreateUri extension method, the generated URI has its query string parameters separated by semi-colons ";" instead of ampersands "&".

The problem seems to be in BinByName in [UriTemplate.cs](https://github.com/openrasta/openrasta-core/blob/2.1/src/OpenRasta/UriTemplate.cs) line 163 :

    path.Append(querySegment.Value.Key).Append("=").Append(parameters[querySegment.Value.Value]).Append(";");

I changed ";" to "&".
Is it the right thing to do?

Thanks