Never fail `make clean'

Mostly some pedantic changes such that `make clean' always ignores
errors. Also changed the top clean target to do the `touch
configs/current' dance instead of realclean.
diff --git a/progs/miniglx/Makefile b/progs/miniglx/Makefile
index 5d0c8ea..d5258b0 100644
--- a/progs/miniglx/Makefile
+++ b/progs/miniglx/Makefile
@@ -43,8 +43,8 @@
 default:  depend $(PROGS)
 
 clean:
-	rm -f $(PROGS)
-	rm -f *.o
+	-rm -f $(PROGS)
+	-rm -f *.o
 
 
 depend: $(SOURCES)