Remove $(TIRPCINC) from all Makefile.am files - it no longer exists

Also, restructure some of the dependencies in the lib/tt binaries.  We
will link with libtt (which will include libtirpc as a dependency),
and XTOOLLIB - all the right X11 stuff without needing to add it to
every OS.  Removed several uneeded OS specializations ("if LINUX",
etc) as a result.

cde/lib/DtSvc/Makefile.am

@@ -6,7 +6,7 @@ libDtSvc_la_LDFLAGS = -version-info 2:1:0
 
 # USe CPPFLAGS so it will apply to both C and C++ components
 libDtSvc_la_CPPFLAGS = -I./include -DMULTIBYTE -DNLS16 -I../include \
-	$(TIRPCINC) @DT_INCDIR@ -DCDE_INSTALLATION_TOP=\"${prefix}\" \
+	@DT_INCDIR@ -DCDE_INSTALLATION_TOP=\"${prefix}\" \
        -DCDE_CONFIGURATION_TOP=\"$(CDE_CONFIGURATION_TOP)\"
 
 if SOLARIS