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()

Change-Id: I01fa2c81643161984eff2625247af75990684bd9
diff --git a/twrp-functions.hpp b/twrp-functions.hpp
index 8e31e42..9f66621 100644
--- a/twrp-functions.hpp
+++ b/twrp-functions.hpp
@@ -50,6 +50,11 @@
 	static bool Fix_su_Perms(void); // sets proper permissions for su binaries and superuser apk
 	static int tw_chmod(string fn, string mode); // chmod function that converts a 4 char string into st_mode automatically
 	static bool Install_SuperSU(void); // Installs su binary and apk and sets proper permissions
+	static vector<string> split_string(const string &in, char del, bool skip_empty);
+	static int Get_File_Type(string fn); // Determines file type, 0 for unknown, 1 for gzip, 2 for OAES encrypted
+	static int Try_Decrypting_File(string fn, string password); // -1 for some error, 0 for failed to decrypt, 1 for decrypted, 3 for decrypted and found gzip format
+	static bool Try_Decrypting_Backup(string Restore_Path, string Password); // true for success, false for failed to decrypt
+	static int Wait_For_Child(pid_t pid, int *status, string Child_Name); // Waits for pid to exit and checks exit status
 	static void Copy_Log(string Source, string Destination);