lib/ccan: namespacize ccan/list to avoid conflict with OpenIndiana's sys/list.h

lib/ccan: namespacize ccan/list to avoid conflict with OpenIndiana's sys/list.h

CCAN includes a little utility called "namespacize" which prepends ccan_ to
all public methods of a module, and fixes up any dependencies it finds.  It's
a little primitive, but it works here.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>