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/dtcreate/Imakefile

@@ -55,12 +55,6 @@ EXTRA_DEFINES = -Xt -D_NO_PROTO
 SYS_LIBRARIES = -lm -ldl -lgen
 #endif /* UXPArchitecture */
 
-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 = \
         main.c          \
         AddFiletype.c   \