FIXES in 2.4.2-BETA-4

Fixed some more bad NULL versus '\0' problems in ftpd.c and realpath.c
in the src directory.

Fixed up the Makefiles for SunOS 4.1.X to make use of the dynamic load
library correctly. This should probably be reworked to only use static 
linking, but that will be looked at another time.

Fixes for HPUX from Derrick J. Brashear. [shadow@johnstown.andrew.cmu.edu]

Replaced a large part of the noretrieve subroutine in extensions.c.


 