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/dtscreen/Imakefile

@@ -11,12 +11,6 @@ LOCAL_LIBRARIES = $(DTSVCLIB) $(TTLIB) $(XMLIB) $(XTOOLLIB) $(XPLIB) $(XLIB)
   SYS_LIBRARIES = -lm -lcrypt
 #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 =	blank.c		dtscreen.c	flame.c		hopalong.c \
 	hsbramp.c	image.c		life.c		pyro.c \
 	qix.c		resource.c	rotor.c		swarm.c \