add 'macos-clean' target to Makefile to get rid of '.DS_Store' files

scripts/Makefile.patch

@@ -29,7 +29,7 @@
  # FIXME: not quite right, since the output name is different
  gallinahtml: GAL=-g
  gallinahtml: html
-@@ -587,6 +593,10 @@
+@@ -585,6 +591,14 @@
  	$(HIDE)rm -f $(CMOFILES:%.cmo=%.cmx)
  .PHONY: archclean
  
@@ -37,6 +37,10 @@
 +	$(SHOW)'VACUUMING *.vo *.glob .*.aux <empty directories>'
 +	$(HIDE)find . -depth \( -iname '*.vo' -or  -iname '*.glob' -or -iname '.*.aux' \)  ! -path './.git/*' -delete
 +	$(HIDE)find . -depth -type d -empty ! -path './.git/*' -delete
++
++macos-clean::
++	$(SHOW)'CLEAN .DS_Store'
++	$(HIDE)find . -depth -iname '.DS_Store' ! -path './.git/*' -delete
  
  # Compilation rules ###########################################################