[Rd] Fix for R-devel+Quartz

[Simon Urbanek]

Current R-devel doesn't compile on OS X, because "-framework Carbon" 
was (correcly) removed main_ldflags, but it was not added to flags for 
grDevices, where it is needed now. The following tiny patch remedies 
the issue (it is sufficient to include AppKit as only that subset of 
Carbon is needed):

Index: src/library/grDevices/src/Makefile.in
===================================================================
--- src/library/grDevices/src/Makefile.in       (revision 32713)
+++ src/library/grDevices/src/Makefile.in       (working copy)
@@ -20,6 +20,8 @@

  # need Defn.h etc, and config.h
  PKG_CPPFLAGS =-I../../../include -I$(top_srcdir)/src/include 
-DHAVE_CONFIG_H
+# need AppKit framework for Quartz (only if Aqua is to be used)
+ at BUILD_AQUA_TRUE@PKG_LIBS =-framework AppKit

  all: Makefile Makedeps
         @$(MAKE) Makedeps

Thanks,
Simon