Mention AutoUnloadPool in the docs where it talks about unloading

Change-Id: I1cf08bba364c0b852abadd0025d0b4de791adca0
typo

Change-Id: Ia24ccb69440de1ff487e41da8d814596904d28b5
Forgot to use Scalar::Util

Change-Id: Ieba6a23c8068d5a233d7372797c56e66565eac77