Superuser: Remove ACCESS_SUPERUSER permission [2/2]

I can't explain this any better than Chainfire, so for that
reason, I'm gonna go ahead and quote him:

Android 5.0 Lollipop now requires custom permissions to be
unique unless the declaring packages are signed with the
same cryptographic keys (same author, usually), or package
installation will fail. As all modern root management
packages now declare this permission, this means you cannot
easily install a different one and start using that one,
as its initial installation will fail, unless you are using
a recovery-based installer that also cleans away the old one.

So let's remove the code behind the permission.

Change-Id: If94b400fb5fb5483e0392adfd863d1112327526b

Conflicts:

	Superuser/src/com/koushikdutta/superuser/util/Settings.java