Add and improve OpenRecoveryScript support

Improve zip finding in ORS engine
Add support for restoring with just a backup name
diff --git a/Android.mk b/Android.mk
index 600f356..347af11 100644
--- a/Android.mk
+++ b/Android.mk
@@ -36,7 +36,8 @@
     partitionmanager.cpp \
     mtdutils/mtdutils.c \
     twinstall.cpp \
-    twrp-functions.cpp
+    twrp-functions.cpp \
+    openrecoveryscript.cpp
 
 ifeq ($(TARGET_RECOVERY_REBOOT_SRC),)
   LOCAL_SRC_FILES += reboot.c