Adapted from FreeBSD. Maintains full backward API / ABI compatbility
with built-in-only nsdispatch().
While here, also make nsdispatch() itself thread-safe.
const char *method /* method name for dynamic linking */
const ns_src defaults[] /* list of defaults */
* bring ns_src into the public arena for above
* make NS_xxx_CB() expand to nothing instead of { src, NULL } - makes
the tables smaller
* convert 'typedef struct xyz { ... } xyz' -> 'typedef struct { ... } xyz'
(which is how it used to be before i experimented with (and ditched) TAILQs)
thorpej