Support encrypted backup files

Also includes features merged from:

Update twrpTar by kokotas

Revised function entryExists().
Added function to get archive's uncompressed size.
Added option to exclude item(s) from the archive.
Revised forks()

http://review.teamw.in/#/c/590/

Change-Id: I01fa2c81643161984eff2625247af75990684bd9
diff --git a/Android.mk b/Android.mk
index 8806616..f393bae 100644
--- a/Android.mk
+++ b/Android.mk
@@ -232,6 +232,11 @@
 ifeq ($(TARGET_BOARD_PLATFORM),rk30xx)
     LOCAL_CFLAGS += -DRK3066
 endif
+ifneq ($(TW_EXCLUDE_ENCRYPTED_BACKUPS), true)
+    LOCAL_SHARED_LIBRARIES += libopenaes
+else
+    LOCAL_CFLAGS += -DTW_EXCLUDE_ENCRYPTED_BACKUPS
+endif
 
 include $(BUILD_EXECUTABLE)
 
@@ -304,7 +309,8 @@
     $(commands_recovery_local_path)/crypto/cryptfs/Android.mk \
     $(commands_recovery_local_path)/libcrecovery/Android.mk \
     $(commands_recovery_local_path)/libblkid/Android.mk \
-    $(commands_recovery_local_path)/minuitwrp/Android.mk
+    $(commands_recovery_local_path)/minuitwrp/Android.mk \
+    $(commands_recovery_local_path)/openaes/Android.mk
 
 ifeq ($(TW_INCLUDE_CRYPTO_SAMSUNG), true)
     include $(commands_recovery_local_path)/crypto/libcrypt_samsung/Android.mk