bundle-uri: add support for http(s):// and file://
The previous change created the 'git clone --bundle-uri=<uri>' option.
Currently, <uri> must be a filename.
Update copy_uri_to_file() to first inspect the URI for an HTTP(S) prefix
and use git-remote-https as the way to download the data at that URI.
Otherwise, check to see if file:// is present and modify the prefix
accordingly.
Reviewed-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>