Refuse carriage return in header value

See bug #1188896.
Comparing with Curl and Django, they both refuse carriage returns in
header values, so the request() method on the HTTP(S)Connection instance
returned by swiftclient.client.http_connection() will raise an
InvalidHeadersException if any of the headers to be sent contain a
newline.

Drive-by fix for a couple of header values which were integers instead
of strings (Content-Length getting set to zero).

Fixes bug #1188896

Change-Id: Ic6afdb92882284f843aacb06d20f682ddcb47151
Merge "Refuse carriage return in header value"