replace usage of char* and apropriate XtFree() by OksXm::AutoCstring in several places of OKS data editor; fix several 0 vs. NULL problems in XtVa(...) functions
replace usage of char* and apropriate XtFree() by OksXm::AutoCstring in several places of OKS data editor; fix several 0 vs. NULL problems in XtVa(...) functions