Wake AIX up from coma

erl_interface has a function in a struct, and AIX headers, when you
use C instead of C++, pollute the global namespace with definitions
that override socket functions, and end up clobbering names of
things Erlang/OTP uses. The new socket interface of R22 was one of
the victims.  I had previously tied to fix it for erl_interface,
but the change broke API public surface. What this does is replace
the name with a define, that defines to the same name on non-AIX,
but uses a "mangled" name on AIX instead. This means internal uses
of this function in the struct need to use the preprocessor define
instead of the "normal" name, and likewise external users too,
but those can be dealt with one-at-a-time on AIX instead of
breaking everyone else.

quick and dirty renaming. the reason why is because AIX has some
network function names prefixed with "n" for spec compliant
versions, and the unprefixed versions are just redfined or are
wrappers. as such, rename the erts/ei functions with these names.

fixes compile on IBM i 7.3

to support zero copy decoding
and bit offset arguments for future unaligned bit strings.