* src/rtl/itemseri.c
! fixed casting for C++ builds
* contrib/rddads/ads1.c
+ use AdsIsNull() function instead of AdsIsEmpty() in DBS_ISNULL
action for ACE library 9.0 or newer.
* contrib/rddads/adsfunc.c
* contrib/rddads/rddads.hbx
+ added new PRG function: AdsIsNull()
For ACE libraries < 9.0 it's redirected to AdsIsEmpty()