connector: Provide the sender's credentials to the callback

Documentation/connector/cn_test.c

Documentation/connector/connector.txt

drivers/connector/cn_queue.c

drivers/connector/connector.c

drivers/md/dm-log-userspace-transfer.c

drivers/staging/dst/dcore.c

drivers/staging/pohmelfs/config.c

drivers/video/uvesafb.c

drivers/w1/w1_netlink.c

include/linux/connector.h