[CIFS] CIFS Stats improvements

New cifs_writepages routine was not updated bytes written in cifs stats.
Also added ability to clear /proc/fs/cifs/Stats by writing (0 or 1) to it.
Signed-off-by: Steve French <sfrench@us.ibm.com>

diff --cc fs/cifs/CHANGES
Simple merge

diff --cc fs/cifs/README
Simple merge

diff --cc fs/cifs/cifs_debug.c
Simple merge

diff --cc fs/cifs/cifs_debug.h
Simple merge

diff --cc fs/cifs/cifsglob.h
Simple merge

diff --cc fs/cifs/connect.c
Simple merge

diff --cc fs/cifs/file.c
Simple merge

diff --cc fs/cifs/netmisc.c
Simple merge

diff --cc fs/cifs/transport.c
Simple merge