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/dtexec/Imakefile

@@ -5,12 +5,6 @@ LOCAL_LIBRARIES = $(TTLIB) $(XTOOLLIB) $(XLIB)
 DEFINES = -DMSGLOG_CLIENT_ONLY
 INCLUDES = -I. 
 
-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 = DtGetMessage.c Main.c MsgLog.c Version.c
 OBJS = DtGetMessage.o Main.o MsgLog.o Version.o