net/http: client should ignore Transfer-Encoding header in HTTP 1.0 responses

HTTP 1.0 doesn't define Transfer-Encoding. The mayor browsers understand this and ignore the header, correctly displaying the response, while the following Go program reports invalid byte in chunk length:

http://play.golang.org/p/SCZOkrJZtI

[gopherbot]

CL https://golang.org/cl/15737 mentions this issue.