WITH LIBEDIT
Libedit won't build on platforms that do not provide
"sys/cdefs.h".
Removed the inclusion of cdefs.h from all files
other that sys.h, which includes this file only
when the header is found while configuring.
It also did not write ~/.mysql_history file. The problem was in alloc(),
which probably does not work on HP-UX-11.23 ia64 platform. Changed some
macros into functions for better maintenance and debugging.
