Clear *.ini and skin directory on installclean

Currently, skin directory remains across different emulator targets, and
need manual removal.  Also, clear hardware-qemu.ini and config.ini.
(See https://android-review.googlesource.com/94692 for config.ini)

Change-Id: Iaa5849ad043ed3f317325ba1d6df287953636f7a
diff --git a/core/cleanbuild.mk b/core/cleanbuild.mk
index fa67332..46a312a 100644
--- a/core/cleanbuild.mk
+++ b/core/cleanbuild.mk
@@ -179,11 +179,13 @@
 	$(HOST_OUT)/obj/NOTICE_FILES \
 	$(HOST_OUT)/sdk \
 	$(PRODUCT_OUT)/*.img \
+	$(PRODUCT_OUT)/*.ini \
 	$(PRODUCT_OUT)/*.txt \
 	$(PRODUCT_OUT)/*.xlb \
 	$(PRODUCT_OUT)/*.zip \
 	$(PRODUCT_OUT)/kernel \
 	$(PRODUCT_OUT)/data \
+	$(PRODUCT_OUT)/skin \
 	$(PRODUCT_OUT)/obj/APPS \
 	$(PRODUCT_OUT)/obj/NOTICE_FILES \
 	$(PRODUCT_OUT)/obj/PACKAGING \