Remove hardcoded CCLINK's in Imakefiles when linking with C++ built libs (DtSvc).

Added proper SharedDtSvcReqs in lnxLib.tmpl and CplusplusLibC in
linux.cf.  This allows the libstdc++ dependancy to be properly
declared for libDtSvc so that it is not neccessary to hardcode 'CCLINK
= g++' in the Imakefiles of programs linking angainst libDtSvc.

cde/programs/dtcalc/Imakefile

@@ -31,12 +31,6 @@ SYS_LIBRARIES = -lm -lgen
 #if defined(HPOSFArchitecture)
 #endif
 
-XCOMM On Linux once you link against a C++ library the whole program 
-XCOMM has to be linked with the C++ linker
-#if defined(LinuxArchitecture)
-CCLINK = $(CXX)
-#endif
-
 SRCS =  calctool.c      ds_common.c     ds_popup.c \
         ds_widget.c     ds_xlib.c       functions.c \
         help.c          motif.c         mp.c \