"scope" should be "slot"

Fixing bug where the current page was not cached as well.

This also generated the cache key automatically, or can be overwritten with a second optional parameter to the remember() method.

[3.0] Fix settings with falsey values not getting returned

Signed-off-by: Micheal Mand <micheal@kmdwebdesigns.com>

Define the warning callback on the SetAppKey

Define the warning callback on the SetAppKey method as getLaravel() doesn't exist - Fixes issue #432