gethostname()'s old and new signatures without requiring a library
bump. Note that programs which called gethostname() with a negative
argument were already broken, since the same type conversion was done
by the old implementation. Add a note in the Makefile so that whoever
next bumps the libc revision will delete the kluge at the same time
(as it will no longer be necessary). This is only operative on 64-bit
platforms.
Submitted by: marcel