core/abuild: add zip archive support

abuild

@@ -160,6 +160,9 @@ unpack() {
 				msg "Unpacking $s..."
 				unlzma -c "$s" | tar -C "$srcdir" -x  \
 					|| return 1;;
+      *.zip)
+        msg "Unpacking $s..."
+        unzip "$s" -d "$srcdir" || return 1;;
 		esac
 	done
 }