fetch: Allow transport -v -v -v to set verbosity to 3

Helpers might want a higher level of verbosity than just +1 (the
porcelain default setting) and +2 (-v -v).  Expand the field to
allow verbosity in the range -1..3.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
CC: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-fetch.c

diff --git a/builtin-fetch.c b/builtin-fetch.c
index cb48c57..52a9a42 100644
--- a/builtin-fetch.c
+++ b/builtin-fetch.c
@@ -665,7 +665,7 @@
 
 	transport = transport_get(remote, remote->url[0]);
 	if (verbosity >= 2)
-		transport->verbose = 1;
+		transport->verbose = verbosity <= 3 ? verbosity : 3;
 	if (verbosity < 0)
 		transport->verbose = -1;
 	if (upload_pack)

transport.h

diff --git a/transport.h b/transport.h
index c14da6f..e4e6177 100644
--- a/transport.h
+++ b/transport.h
@@ -25,7 +25,7 @@
 
 	int (*disconnect)(struct transport *connection);
 	char *pack_lockfile;
-	signed verbose : 2;
+	signed verbose : 3;
 	/* Force progress even if the output is not a tty */
 	unsigned progress : 1;
 };