Don't look up protocol number for TCP (getprotobyname).  (Likely) due to some
strange threading issue, it can hang.  Since this number has been the same
since the beginning of Internet time and will continue to be the same til the
heat death of the universe, there really isn't much reason for a dynamic
lookup.  Instead, we just let the kernel choose.

Proliferate the use of lib_lock a bit more.  For the stated purpose of
protecting libc memory allocation, there were some questionable areas that
I have added locking to.  This really shouldn't be needed anymore, but til
we can shed our ancient disk images, the code remains.