Export DIRLINK and DIRUNLINK from main Makefile, to be able to use that from apps/Application.mk

Makefile.unix

@@ -56,8 +56,8 @@ endif
 # Default tools
 
 ifeq ($(DIRLINK),)
-DIRLINK = $(TOPDIR)/tools/link.sh
-DIRUNLINK = $(TOPDIR)/tools/unlink.sh
+export DIRLINK = $(TOPDIR)/tools/link.sh
+export DIRUNLINK = $(TOPDIR)/tools/unlink.sh
 endif
 
 # This define is passed as EXTRADEFINES for kernel-mode builds.  It is also passed