Stupid SU: Galaxy S4 root helper by François SIMOND aka @supercurio

Circumvent an extremely weak false-security "Anti Root" mechanism implemented
on latest Samsung Galaxy S4 devices (on both Exynos and Qualcomm versions)

Preventing proper root function on official firmware breaks all my Voodoo apps
requiring stock+root and is a move that's hostile to both users and developers.

Samsung security might be embarassed by this proof of concept, as it defeats
their mechanism in a single line... not even with complex ARM assembler
but *one* line of shell script.
However, the goal here is to show Superuser solutions developers how to
deal with those devices for now, and provide a working solution to people who
bought a Galaxy S4 expecting to root it cleanly and easily but cannot.

This proof of concept is slightly slowing down Superuser calls, but its
"plain text" implementation has the merit of showing how stupid this exploit is.

SELinux configuration stays unmodified and active.

Features:
- Detect and supports both SuperSU and Koush's Superuser
- Installs Super SU binary by default

Make sure you have one of those Superuser apps installed:
- https://play.google.com/store/apps/details?id=com.koushikdutta.superuser
- https://play.google.com/store/apps/details?id=eu.chainfire.supersu

Root feature doesn't rely on a "StupidSU kernel" which is only an installer.
Feel free to flash back Samsung's original boot.img from their official firmware
after booting at least once.

Important Note:
This "exploit" is so lame that it will be fixed in no time, making updated S4
a pain to root again.

I wish Samsung will reconsider their "Anti Root" approach, which is damageable
in every regard and defective by design as demonstrated here.
Also, I'm simply not interested developing for and promoting devices from
manufacturers hostile to developers: It's just a waste of valuable time.

XDA Thread:
	http://forum.xda-developers.com/showthread.php?t=2283485 (I9500 dev)